Pumping system with precise ratio output

ABSTRACT

A precision pumping system is disclosed. The pumping system includes an electric motor assembly powering a first drive shaft driving a first pump at a first flow rate and powering a second drive shaft driving a second pump at a second flow rate. A proportioned fluid output includes a first fluid pumped by the first pump and a second fluid pumped by the second pump. The pumping system provides a desired ratio of the first fluid to the second fluid at the proportioned fluid output, relatively independently of pressure and flow rate at the output.

TECHNICAL FIELD

The disclosure is directed to a precision pumping system. More particularly, the disclosure is directed to a pumping system whose fluid output includes desired proportions of two or more input fluids.

BACKGROUND

In many fluid applications, such as chemical applications, one or more fluids must be mixed with one or more additional fluids to achieve a desired fluid mixture. Commonly, mixing one fluid with another fluid is performed by measuring out a quantity of a first fluid, measuring out a quantity of a second fluid, and combining the measured amounts in a container where the fluids are mixed together. This process is routinely performed by hand, and thus is subject to inaccuracies attributed to human error. Thus, the fluid mixture achieved may not in fact possess the precise desired proportions of the fluids. Additionally, as fluid mixtures are typically mixed in batches (i.e., discrete quantities of a fluid mixture), inconsistencies in the proportions of the mixed fluids from one batch to the next batch may be experienced.

What is desired is a pumping system which outputs a fluid mixture of two or more fluids, in which accurate and precise proportions of the fluids are maintained in the fluid mixture output from the system.

SUMMARY

Disclosed is a precision pumping system whose fluid output includes desired proportions of two or more input fluids.

Accordingly, one illustrative embodiment is a pumping system that includes an electric motor assembly powering a first drive shaft driving a first pump at a first flow rate and powering a second drive shaft driving a second pump at a second flow rate. A proportioned fluid output includes a first fluid pumped by the first pump and a second fluid pumped by the second pump. The pumping system provides a desired ratio of the first fluid to the second fluid at the proportioned fluid output, relatively independently of pressure and flow rate at the output.

Another illustrative embodiment is a system for pumping a first fluid and a second fluid in a desired proportion. The system includes a first pump having an inlet in fluid communication with a first container for holding a quantity of the first fluid, and an outlet. The system further includes a second pump having an inlet in fluid communication with a second container for holding a quantity of the second fluid, and an outlet. The system further includes an electric motor assembly for driving the first pump at a first cycling rate and the second pump at a second cycling rate, wherein the outlet of the first pump and the outlet of the second pump are in fluid communication with an outlet of the system, sometimes through respective check valves to prevent backflow.

Yet another illustrative embodiment is a system for pumping a first fluid and a second fluid in a desired proportion. The system includes a first pump, a second pump, a third pump, a fourth pump, and an electric motor assembly. The first pump has an inlet in fluid communication with a first container for holding a quantity of the first fluid, and an outlet. The second pump has an inlet in fluid communication with a second container for holding a quantity of the second fluid, and an outlet. The outlet of the first pump and the outlet of the second pump are in fluid communication with a first stage outlet. The electric motor assembly drives the first pump at a first cycling rate and drives the second pump at a second cycling rate. The third pump has an inlet in fluid communication with the second container, and an outlet. The fourth pump has an inlet in fluid communication with the first stage outlet, and an outlet. The outlet of the third pump and the outlet of the fourth pump are in fluid communication with a second stage outlet. The third pump is driven at a third cycling rate and the fourth pump is driven at a fourth cycling rate. In some embodiments the third pump and the fourth pump are driven by another electric motor assembly.

The above summary of some example embodiments is not intended to describe each disclosed embodiment or every implementation of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be more completely understood in consideration of the following detailed description of various embodiments in connection with the accompanying drawings, in which:

FIG. 1 is a perspective view of an exemplary pump assembly;

FIG. 2 is an exploded view of the exemplary pump assembly of FIG. 1;

FIG. 3 is a view of a pump of the pump assembly of FIG. 1 illustrating the eccentric drive means of the pump;

FIG. 4 is a view of the interaction of the eccentric drive means with the electric motor and the piston of the pump of the pump assembly of FIG. 1;

FIG. 5 is an exploded view of a pump of the pump assembly of FIG. 1;

FIG. 6 is a partially cut away view of a pump of the pump assembly of FIG. 1;

FIG. 7 is a perspective view of the manifold of a pump of the pump assembly of FIG. 1;

FIG. 7A is a partially cut away view of the manifold of FIG. 7;

FIG. 8 is a perspective view of a housing block of a pump of the pump assembly of FIG. 1;

FIG. 8A is a partially cut away view of the housing block of FIG. 8;

FIG. 9 is an exploded view of a valve assembly of a pump of the pump assembly of FIG. 1;

FIG. 9A is a cross sectional view of the valve assembly of FIG. 9 in an assembled configuration;

FIG. 9B is a cross sectional view of a valve assembly similar to the valve assembly shown in FIG. 9A;

FIG. 9C is a cross sectional view of a valve assembly similar to the valve assembly shown in FIG. 9A;

FIG. 10 is an exploded view of another valve assembly which may be used in the pump assembly of FIG. 1;

FIG. 10A is a cross sectional view of the valve assembly of FIG. 10 in an assembled configuration;

FIGS. 11 and 12 are perspective views of an exemplary pumping system including the pumping assembly of FIG. 1;

FIG. 13 is a schematic diagram of the pumping system of FIGS. 1 and 12;

FIG. 14 is a perspective view of another exemplary pumping system including the pumping assembly of FIG. 1;

FIG. 15 is a schematic diagram of the pumping system of FIG. 14;

FIG. 16 is a schematic diagram of another exemplary pumping system including a plurality of the pumping assemblies of FIG. 1;

FIG. 17 is a schematic diagram of yet another exemplary pumping system including a plurality of the pumping assemblies of FIG. 1;

FIG. 18 depicts an exemplary pumping system including a control module;

FIG. 19A is a diagram illustrating an exemplary functionality of a control system for use with the pumping system of FIG. 18;

FIG. 19B is a diagram illustrating another exemplary functionality of a control system for use with the pumping system of FIG. 18; and

FIG. 19C is a diagram illustrating another exemplary functionality of a control system for use with the pumping system of FIG. 18.

While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit aspects of the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

DETAILED DESCRIPTION

For the following defined terms, these definitions shall be applied, unless a different definition is given in the claims or elsewhere in this specification.

All numeric values are herein assumed to be modified by the term “about”, whether or not explicitly indicated. The term “about” generally refers to a range of numbers that one of skill in the art would consider equivalent to the recited value (i.e., having the same function or result).

The recitation of numerical ranges by endpoints includes all numbers within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

Although some suitable dimensions ranges and/or values pertaining to various components, features and/or specifications are disclosed, one of skill in the art, incited by the present disclosure, would understand desired dimensions, ranges and/or values may deviate from those expressly disclosed.

As used in this specification and the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.

The following detailed description should be read with reference to the drawings in which similar elements in different drawings are numbered the same. The detailed description and the drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the invention. The illustrative embodiments depicted are intended only as exemplary. Selected features of any illustrative embodiment may be incorporated into an additional embodiment unless clearly stated to the contrary.

An exemplary pump assembly 10 is shown in FIGS. 1 and 2. The pump assembly 10 may include a first pump 12, a second pump 14, and an electric motor assembly 20 powering the first pump 12 and the second pump 14. The electric motor assembly 20 is shown in FIG. 1 as being positioned between the first pump 12 and the second pump 14. As shown in FIG. 1, rotational power generated by the electric motor assembly 20 is transmitted to each of the first pump 12 and the second pump 14 in order to actuate the pumps 12/14. However, in other embodiments the electric motor assembly 20 may otherwise be connected to the first pump 12 and/or the second pump 14 such that power generated by the electric motor assembly is transmitted to the first pump 12 and/or the second pump 14.

The electric motor assembly 20 may include an electric motor 22 including a first drive shaft 24. In some embodiments, the first drive shaft 24 may extend from the first end 26 of the electric motor 22, and the first drive shaft 24 may extend from the second end 28 of the electric motor 22. The electric motor 22 may rotate the first drive shaft 24 at a first rotational speed. For instance, in some embodiments the electric motor 22 may rotate the first drive shaft 24 at a rotational speed in the range of about 160° revolutions per minute (RPM) to about 3600 RPM, although other speeds are contemplated.

A transmission 30 may be connected to the electric motor 22 to transmit power from the electric motor 22. As shown in FIG. 1, the first end 32 of the transmission 30 may be attached to the second end 28 of the electric motor 22. The first drive shaft 24 may extend into or otherwise be connected to the transmission 30. A second drive shaft 34 may extend from the second end 36 of the transmission 30. Thus, the first drive shaft 24 extending from the second end of 28 of the electric motor 22 may be the power input into the transmission 30, and the second drive shaft 34 extending from the second end 36 of the transmission 30 may be the power output from the transmission 30. In some embodiments, the second drive shaft 34 may be axially aligned with the first drive shaft 24. In other embodiments, the second drive shaft 34 may be offset, or otherwise not axially aligned with the first drive shaft 24.

As used herein a transmission is an assembly of associated parts by which rotational power is converted from a first rotational speed or rate at the power input of the transmission to a second, different, rotational speed or rate at the power output of the transmission. As used herein the terms “speed” or “rate” may refer to a fixed speed or rate or a variable speed or rate unless the content clearly dictates otherwise.

In some embodiments, the transmission may include one or more chains and sprockets, one or more belts and pulleys, one or more gears, etc. used to alter the output speed from the input speed. In some embodiments, the transmission may be a speed reduction, such as a gear reduction including one or more gears reducing the rotational rate of the output shaft from the rotational rate of the input shaft, while in other embodiments the transmission may be a speed accelerator, such as a gear accelerator including one or more gears increasing the rotational rate of the output shaft from the rotational rate of the input shaft.

Thus, the transmission 30 may be present to control the rotational rate of the second drive shaft 34 relative to the first drive shaft 24. For instance, the first drive shaft 24 may be rotated at a first rotational rate and the second drive shaft 34 may be rotated at a second rotational rate. In some embodiments, the first rotational rate may be the same as the second rotational rate, or the first rotational rate may be different from the second rotational rate. For instance, in some embodiments the rotational rate of the first drive shaft 24 may be greater than the rotational rate of the second drive shaft 34, while in other embodiments the rotational rate of the first drive shaft 24 may be less than the rotational rate of the second drive shaft 34.

In some embodiments, the transmission 30 may be configured such that the first drive shaft 24 has a rotational rate of in the range of 2 to 100 times, in the range of 5 to 50 times, in the range of 10 to 40 times, or in the range of 20 to 30 times the rotational rate of the second drive shaft 34. In some embodiments the rotational rate of the first drive shaft 24 may be 2 times, 4 times, 8 times, 12 times, 24 times, 36 times, 40 times or 50 times the rotational rate of the second drive shaft 34.

In some embodiments, the transmission 30 may be configured such that the second drive shaft 34 has a rotational rate of in the range of 2 to 100 times, in the range of 5 to 50 times, in the range of 10 to 40 times, or in the range of 20 to 30 times the rotational rate of the first drive shaft 24. In some embodiments the rotational rate of the second drive shaft 34 may be 2 times, 4 times, 8 times, 12 times, 24 times, 36 times, 40 times or 50 times the rotational rate of the first drive shaft 24.

It is noted, however, that these exemplary rates are for illustrative purposes only, and the transmission 30 may rotate the second drive shaft 34 at any desired rate relative to the first drive shaft 24.

In some embodiments the rotational rate of the first drive shaft 24 may be a fixed rate of rotation. However, in other embodiments the rotational rate of the first drive shaft 24 may be a variable rate of rotation which may be selectively controlled. For example, in some embodiments a controller may be used to adjust the rotational rate of the first drive shaft 24 to a desired rate of rotation. For instance, a controller may be used to vary the speed of the motor 22 in order to adjust the rotational rate of the first drive shaft 24. In such instances the rotational rate of the first drive shaft 24 may be manually controlled by an operator, or the rotational rate of the first drive shaft 24 may be electronically controlled with signals generated by a processor of the controller, for example signals generated from feedback response provided to the controller.

In some embodiments, the motor 22 may be configured to run at variable speeds. Thus, the rotational rate of the first drive shaft 24 may be varied by varying the speed of the motor 22. In such embodiments, when the transmission 30 is fixed or otherwise not varied, varying the rotational rate of the first drive shaft 24 with the speed control module 288 varies the rotational rate of the second drive shaft 34 in proportion to the ratio dictated by the transmission 30. Thus, varying the speed of the motor 22 may vary the flow rate of fluid pumped through the first pump 12 and the flow rate of fluid pumped through the second pump 14, while maintaining a constant proportion or ratio of the fluid pumped through the first pump 12 to the fluid pumped through the second pump 14.

In some embodiments the rotational rate of the second drive shaft 34 may be a fixed rate of rotation. However, in other embodiments the rotational rate of the second drive shaft 34 may be a variable rate of rotation which may be selectively controlled. For example, in some embodiments a controller may be used to adjust the rotational rate of the second drive shaft 34 to a desired rate of rotation. For instance, a controller may be used send a signal to the transmission 30 in order to adjust the rotational rate of the second drive shaft 34. In such instances the rotational rate of the second drive shaft 34 may be manually controlled by an operator, or the rotational rate of the second drive shaft 34 may be electronically controlled with signals generated by a processor of the controller, for example signals generated from feedback response provided to the controller.

The first pump 12 may be driven by rotation of the first drive shaft 24, while the second pump 14 may be driven by rotation of the second drive shaft 34. In embodiments in which the rotational rate of the first drive shaft 24 is different from the rotational rate of the second drive shaft 34, the first pump 12 may be actuated at a different rate from the second pump 14. In embodiments in which the displacement of the first pump 12 is the same as the displacement of the second pump 14, the fluid output rate of the first pump 12 may be different from the fluid output rate of the second pump 14 when the drive shafts 24/34 are rotated at different rates. For instance, in some embodiments, the fluid output rate of the first pump 12 may be greater than or less than the fluid output rate of the second pump 14.

In some embodiments, the fluid output rate of the first pump 12 may be different from the fluid output rate of the second pump 14 when the first pump 12 has a different displacement than the second pump 14. In such embodiments, the rotational rate of the first drive shaft 24 powering the first pump 12 may be the same as or different than the rotational rate of the second drive shaft 34.

In some embodiments the fluid output rate of the first pump 12 may be proportional to the rotational rate of the first drive shaft 24, while the fluid output rate of the second pump 14 may be proportional to the rotational rate of the second drive shaft 34. In some embodiments the fluid output from the first pump 12 may be in the range of 2 to 100 times, in the range of 2 to 50 times, in the range of 10 to 40 times, in the range of 20 to 40 times, in the range of 20 to 50 times, or in the range of 50 to 100 times the fluid output of the second pump 14. Thus, in some embodiments, the fluid output from the first pump 12 may be 2 times, 4 times, 8 times, 12 times, 24 times, 36 times, 40 times or 50 times the fluid output from the second pump 14. In other embodiments the fluid output from the second pump 14 may be in the range of 2 to 100 times, in the range of 2 to 50 times, in the range of 10 to 40 times, in the range of 20 to 40 times, in the range of 20 to 50 times, or in the range of 50 to 100 times the fluid output of the first pump 12. Thus, in other embodiments, the fluid output from the second pump 14 may be 2 times, 4 times, 8 times, 12 times, 24 times, 36 times, 40 times or 50 times the fluid output from the first pump 12. It is noted, however, that these possible fluid output ratios are for illustrative purposes only, and any desired fluid ratio may be achieved.

Thus, it can be seen that the displacement of the pumps 12/14 and/or the input/output speed ratio of the transmission 30 may be selected to achieve a desired fluid mixture having a desired proportion of a first fluid pumped by the first pump 12 and a desired proportion of a second fluid pumped by the second pump 14, relatively independently of pressure and flow rate at the output. Therefore, in some embodiments, the displacement of the pumps 12/14 and/or the input/output speed ratio of the transmission 30 may be selected to attain a label dictated rate of a chemical mixed with a fluid such as water. Thus, regardless of the speed of the motor 22 (and thus the flow rate of fluids through the pumps 12/14) the proportion or ratio of the fluid pumped through the first pump 12 to the fluid pumped through the second pump 14 may be constant. Therefore, the ratios of fluids pumped through the pumps 12/14 may be accurately controlled.

The first pump 12 and/or the second pump 14 may be any desired pump. For example, the first pump 12 and the second pump 14 may be rotodynamic pumps or positive displacement pumps. In some embodiments the pumps 12/14 may be piston pumps, plunger pumps, gear pumps, impeller pumps, or the like. For illustrative purposes, both the first pump 12 and the second pump 14 are shown as double acting simplex positive displacement plunger pumps. Double acting means that each stroke of the plunger results in both suction and discharge of fluid. Simplex means that the pump utilizes a single plunger. Some examples of double acting simplex positive displacement plunger pumps are described in U.S. Pat. Nos. 4,978,284, 5,173,039, 5,183,396, 6,257,843 and 6,527,524, the disclosures of which are incorporated herein by reference. In other embodiments, the positive displacement plunger pumps may be single acting and/or duplex or triplex pumps.

The first pump 12 and its components will now be described in greater detail while referring to FIGS. 3-10. Although discussion is directed to the first pump 12, it is understood that the discussion of the construction, function and/or operation of the first pump 12 may be equally applicable to the construction, function and/or operation of the second pump 14.

FIG. 3 shows the pump 12 in an assembled state. As shown in FIG. 3, the pump 12 may include a first housing block 40 a, a second housing block 40 b, and a manifold 42. A piston 44 may extend between the first housing block 40 a and the second housing block 40 b. The piston 44 may extend through supports 46 a/46 b, positioning the piston 44 within piston bores of the first housing block 40 a and the second housing block 40 b.

An eccentric drive means 50 may be used to effectuate reciprocating movement of the piston 44 within the pump 12. The eccentric drive means 50 may include a cam 52 surrounded by a bearing 54. The cam 52 may be a cylindrical member with an offset opening 56 into which a drive shaft fits. For instance, the first drive shaft 24 or the second drive shaft 34 may extend into or through the opening 56 of the cam 52 in order to secure the cam 52 to the drive shaft 24/34.

The opening 56 of the cam 52 is not centered on the central axis of the cam 52. Thus, as rotation of the drive shaft 24/34 rotates the cam 52, the outer periphery of the cam 52 does not remain stationary. As the cam 52 and bearing 54 are disposed in the recess 48 of the piston 44, rotation of the cam 52 results in reciprocating motion of the piston 44. Thus, one revolution of the drive shaft 24/34 rotates the cam 52 one revolution, which in turn results in one stroke of the piston 44. A stroke of the piston 44 is defined as a single back-and-forth cycle of the piston in which the piston 44 travels from its furthest extent in a first direction (e.g., toward the first housing block 40 a) to its furthest extent in the opposite direction (e.g., toward the second housing block 40 b) and back to its furthest extent in the first direction.

The volume of fluid output by the pump 12 during one stroke of the piston 44 is considered the displacement of the pump 12. The displacement of the pump 12 is a function of the diameter of the piston 44 and the stroke length (e.g., longitudinal movement) of the piston 44. Thus, in some embodiments the displacement of the pump 12 may be changed by changing the diameter of the piston 44 and/or the stroke length of the piston 44. In some embodiments, a sleeve may be placed in the piston bore to accommodate a piston having a smaller diameter. Additionally and/or alternatively, in some embodiments the cam 52 may be substituted with another cam having a different eccentricity, such as the opening of the cam being located at a different radial position from the center axis of the cam.

FIG. 4 more clearly shows the relationship between the cam 52, bearing 54 and the recess 48 of the piston 44. Additionally, the end portions of the piston 44 are shown extending through the supports 46 a/46 b, with seals 58 positioned around the piston 44 to prevent fluid from leaking past the supports 46 a/46 b. The outer periphery of the bearing 54 may be in contact with the recess 48 of the piston 44, and the cam 52 may be positioned in the central opening of the bearing 54. Thus, the bearing 54 may surround the cam 52.

FIG. 5 is an exploded view showing components of the pump 12. As described above, the pump 12 includes a first housing block 40 a, a second housing block 40 b, a piston 44 and a manifold 42. Additional internal components are shown in FIG. 5. The pump 12 may include a pair of check valves 70 positioned in each of the housing blocks 40 a/40 b. Seals 80 may be used to prevent fluid leakage past the interface between the valves 70 and the housing blocks 40 a/40 b.

As shown, the first housing block 40 a may include a first check valve 70 a allowing one directional fluid flow into the interior of the first housing block 40 a, and a second check valve 70 b allowing one directional fluid flow out from the interior of the first housing block 40 a. Similarly, the second housing block 40 b may include a first check valve 70 a allowing one directional fluid flow into the interior of the second housing block 40 b, and a second check valve 70 b allowing one directional fluid flow out from the interior of the second housing block 40 b. The first check valve 70 a may be substantially identical in configuration to the second check valve 70 b, with only the orientation of the check valve reversed. In other embodiments, the first check valve 70 a may be of a different configuration than the second check valve 70 b.

A first check valve 70 a of the pump 12 may be disposed in an inlet valve bore 62 a of the first housing block 40 a and a second check valve 70 b of the pump 12 may be disposed in an outlet valve bore 64 a of the first housing block 40 a. Similarly, a first check valve 70 a of the pump 12 may be disposed in an inlet valve bore 62 b of the second housing block 40 b and a second check valve 70 b of the pump 12 may be disposed in an outlet valve bore 64 b of the second housing block 40 b.

The first housing block 40 a may also include a piston bore 60 a into which an end portion of the piston 44 extends into. Similarly, although not shown in FIG. 5, the second housing block 40 b may also include a piston bore into which an opposite end portion of the piston 44 extends into.

Additional discussion of the first housing block 40 a will be discussed while referring to FIGS. 8 and 8A. As described above, the pump 12 includes a first housing block 40 a and a second housing block 40 b. Each of the housing blocks 40 a/40 b may be of similar construction. Although discussion is directed to the first housing block 40 a, it is understood that the discussion of the construction, function and/or operation of the first housing block 40 a may be equally applicable to the construction, function and/or operation of the second housing block 40 b.

As discussed above, the first housing block 40 a may include an inlet valve bore 62 a, an outlet valve bore 64 a, and a piston bore 60 a. As shown in the cross-sectional view of the first housing block 40 a in FIG. 8A, the piston bore 60 a may be in fluid communication with each of the inlet valve bore 62 a and the outlet valve bore 64 a. Thus, it can be understood that during operation, actuation of the piston 44 to the left in FIG. 8 would create a suction within the piston bore 60 a, drawing fluid through the inlet valve 70 a positioned in the inlet valve bore 62 a and into the piston bore 60 a. As the outlet valve 70 b positioned in the outlet valve bore 64 a may be a one-way valve, fluid is prevented from entering the piston bore 60 a through the outlet valve 70 b when suction is created in the piston bore 60 a. Actuation of the piston 44 to the right in FIG. 8 would force fluid out of the piston bore 60 a through the outlet valve 70 b positioned in the outlet valve bore 64 a. As the inlet valve 70 a positioned in the inlet valve bore 62 a may be a one-way valve, fluid is prevented from exiting the piston bore 60 a through the inlet valve 70 a when pressure is created in the piston bore 60 a.

Referring back to FIG. 5, the pump 12 may include a manifold 42 having a plurality of ports and/or bores. The manifold 42 may be fastened to the first housing block 40 a and the second housing block 40 b, enclosing the valves 70 between the manifold 42 and the housing blocks 40 a/40 b. The manifold 42 includes a first inlet bore 66 a, a second inlet bore 66 b, a first outlet bore 68 a, and a second outlet bore 68 b.

Additional discussion of the manifold 42 will be discussed while referring to FIGS. 7 and 7A. The manifold 42 may include a first inlet valve bore 72 a, a second inlet valve bore 72 b, a first outlet valve bore 74 a, and a second outlet valve bore 74 b. The first inlet valve bore 72 a of the manifold 42 may be aligned with and/or in fluid communication with the first inlet valve bore 62 a of the first housing block 40 a, and the first outlet valve bore 74 a of the manifold 42 may be aligned with and/or in fluid communication with the first outlet valve bore 64 a of the first housing block 40 a. Similarly, the second inlet valve bore 72 b of the manifold 42 may be aligned with and/or in fluid communication with the second inlet valve bore 62 b of the second housing block 40 b, and the second outlet valve bore 74 b of the manifold 42 may be aligned with and/or in fluid communication with the second outlet valve bore 64 b of the second housing block 40 b.

The manifold 42 may also include one or more inlet bores and/or one or more outlet bores. The manifold 42 is shown as including a first inlet bore 66 a extending from a first inlet port, a second inlet bore 66 b extending from a second inlet port, a first outlet bore 68 a extending from a first outlet port, and a second outlet bore 68 b extending from a second outlet port. The first inlet bore 66 a may be in fluid communication with the first inlet valve bore 72 a, and the first outlet bore 68 a may be in fluid communication with the first outlet valve bore 74 a. Similarly, the second inlet bore 66 b may be in fluid communication with the second inlet valve bore 72 b, and the second outlet bore 68 b may be in fluid communication with the second outlet valve bore 74 b.

As shown in FIG. 7A, in some embodiments the first inlet bore 66 a may be in fluid communication with the second inlet bore 66 b, and/or the first outlet bore 68 a may be in fluid communication with the second outlet bore 68 b. In other embodiments, the first inlet bore 66 a may not be in fluid communication with the second inlet bore 66 b, and/or the first outlet bore 68 a may not be in fluid communication with the second outlet bore 68 b. In some embodiments, the manifold 42 may include only one inlet bore in fluid communication with both the first inlet valve bore 72 a and the second inlet valve bore 72 b, and/or the manifold 42 may include only one outlet bore in fluid communication with both the first outlet valve bore 74 a and the second outlet valve bore 74 b.

A fluid may flow into the inlet bore 66 a/66 b from a fluid source, such as a fluid container, and into the inlet valve bores 72 a/72 b. During the suction portion of the stroke of the piston 44, the fluid may be drawn through the inlet valve 70 a of the pump 12 into the piston bore 60 a/60 b. During the pressure portion of the stroke of the piston 44, the fluid may be expelled from the piston bore 60 a/60 b through the outlet valve 70 b of the pump 40, into the outlet valve bores 74 a/74 b and out of the pump 12 through the outlet bore 68 a/68 b. It is noted that when the pump 12 is a double-acting plunger pump, suction will be experienced in the piston bore 60 a of the first housing block 40 a as pressure is experienced in the piston bore 60 b of the second housing block 40 b. Likewise, suction will be experienced in the piston bore 60 b of the second housing block 40 b as pressure is experienced in the piston bore 60 a of the first housing block 40 a.

Fittings, such as hose fittings, may be coupled to the inlet and outlet bores of the manifold as desired to couple fluid inlet and fluid outlet lines (e.g., hoses, pipes, etc.) to the pump 12. Such fittings may include elbows, tees, reducers, couplers, caps, ball valves, stopcock valves, or the like.

FIG. 6 shows a cut away of the pump 12 with the second housing block 40 b removed and the first housing block 40 a partially cut away, so that the interaction of the piston 44 with the various components of the housing block 40 a and manifold 42 may more easily be understood. The inlet valve bore 62 a, the outlet valve bore 64 a, and the piston bore 60 a may collectively create a cavity within the first housing block 40 a. During operation, the piston 44 may reciprocate back-and-forth in the piston bore 60 a, changing the volume of the cavity of the first housing block 40 a. Depending on the portion of the stroke cycle of the piston 44, fluid may either be drawn into the cavity of the first housing block 40 a or expelled from the cavity of the first housing block 40 a, creating a fluid pumping action through the pump 12. Although not shown in FIG. 6, the interaction of the piston 44 with the bores of the housing block 40 b would be similar.

Additional discussion of the valves 70 within the pump 12 will be discussed while referring to FIGS. 9, 9A, 9B and 9C. The valve 70 is shown in an exploded view in FIG. 9. The valve 70 includes a housing 82, a poppet 84, a spring 86, and a retainer 88.

As shown in FIG. 9A, when assembled the surface 83 of the housing 82 faces the surface 85 of the poppet 84. The spring 86, which is located on the other side of the poppet 84, is compressed between the retainer 88 and the poppet 84. The compressive forces of the spring 86 urge the surface 85 of the poppet 84 into contact with the surface 83 of the housing 82. The retainer 88 holds the spring 86 in place.

The valve 70 opens and closes depending on the pressure differential across the poppet 84 of the valve 70. During operation, pressurized fluid passes through the opening 81 of the housing 82 into contact with the poppet 84. Forces generated by the pressurized fluid on the poppet 84 oppose the forces generated by the spring 86. While the forces generated by the spring 86 remain greater than the forces generated by the pressured fluid, the surface 85 of the poppet 84 remains in contact with the surface 83 of the housing 82. Contact between the poppet 84 and the housing 82 prevents fluid to pass through the valve 70. As the forces generated by the pressurized fluid on the poppet 84 exceed the forces generated by the spring 86, the poppet 84 moves away or lifts off of the housing 82. Thus, a gap is formed between the surface 85 of the poppet 84 and the surface 83 of the housing 82. Fluid is then allowed to pass through the gap between the poppet 84 and the housing 82 in order to pass through the valve 70. When the forces of the pressurized fluid are again less than the forces generated by the spring 86, the poppet 84 moves into contact with the housing 82, eliminating the gap between the components and thus stopping the flow of fluid through the valve 70.

Alternatively, during operation a vacuum may be created on the spring-side of the poppet 84. When the vacuum exceeds a threshold level, the poppet 84 is pulled away from or lifts off of the housing 82, forming a gap between the surface 85 of the poppet 84 and the surface 83 of the housing 82. Fluid is then drawn through the gap between the poppet 84 and the housing 82 and across the valve 70.

FIG. 9B shows an alternate embodiment of the valve 70. As shown in FIG. 9B, an elastomeric member 90 (e.g., an O-ring) may be placed between the housing 82 and the poppet 84, forming a seal between the two components of the valve 70. As shown in FIG. 9B, the housing 82 may include a channel 87 formed in the housing 82 configured to retain the elastomeric member 90. The channel 87 may include a bottom surface 93 and two side surfaces 91 and 92 extending from the bottom surface 93 to the surface 83 of the housing 82. In some embodiments one or both of the two side surfaces 91/92 may be formed at an oblique angle to the bottom surface 93. In some embodiments, the angle between the bottom surface 93 of the channel 87 and each of the side surfaces 91/92 of the channel 87 may be an acute angle, for example. The side surfaces 91/92 may taper toward one another as the side surfaces 91/92 approach the surface 83 of the housing 82, thus narrowing the channel 87 toward the surface 83 of the housing 82.

An elastomeric member 90 may be placed in the channel 87 through the opening of the channel 87 at the surface 83 of the housing 82. In some embodiments, the distance across the opening of the channel 87 between the first side surface 91 and the second side surface 92 may be less than the diameter of the elastomeric member 90. The elastomeric member 90 may be slightly compressed to fit the elastomeric member 90 through the opening at the surface 83 of the housing 82. However, once placed in the channel 87, the elastomeric member 90 may at least partially expand such that the elastomeric member 90 may be sufficiently retained in the channel 87. The relative sizes of the elastomeric member 90 and the distance across the opening of the channel 87 between the first side surface 91 and the second side surface 92 may inhibit the elastomeric member 90 from coming out of the channel 87.

FIG. 9C shows another alternate embodiment of the valve 70. As shown in FIG. 9C, an elastomeric member 90 (e.g., an O-ring) may be placed between the housing 82 and the poppet 84, forming a seal between the two components of the valve 70. As shown in FIG. 9C, the poppet 84 may include a channel 87 formed in the poppet 84 configured to retain the elastomeric member 90. The channel 87 may include a bottom surface 93 and two side surfaces 91 and 92 extending from the bottom surface 93 to the surface 85 of the poppet 84. In some embodiments one or both of the two side surfaces 91/92 may be formed at an oblique angle to the bottom surface 93. In some embodiments, the angle between the bottom surface 93 of the channel 87 and each of the side surfaces 91/92 of the channel 87 may be an acute angle, for example. The side surfaces 91/92 may taper toward one another as the side surfaces 91/92 approach the surface 85 of the poppet 84, thus narrowing the channel 87 toward the surface 85 of the poppet 84.

An elastomeric member 90 may be placed in the channel 87 through the opening of the channel 87 at the surface 85 of the poppet 84. In some embodiments, the distance across the opening of the channel 87 between the first side surface 91 and the second side surface 92 may be less than the diameter of the elastomeric member 90. The elastomeric member 90 may be slightly compressed to fit the elastomeric member 90 through the opening at the surface 85 of the poppet 84. However, once placed in the channel 87, the elastomeric member 90 may at least partially expand such that the elastomeric member 90 may be sufficiently retained in the channel 87. The relative sizes of the elastomeric member 90 and the distance across the opening of the channel 87 between the first side surface 91 and the second side surface 92 may inhibit the elastomeric member 90 from coming out of the channel 87.

FIG. 10 is an exploded view of another valve 570 which may be used in a pump 12. The valve 570 may include a poppet 584, a spring 586 and an elastomeric member 590 (e.g., O-ring).

FIG. 10A shows the valve 570 assembled within a pump housing. The valve 570 may be positioned between a fluid passageway 589 of a first housing portion 540 (e.g., the housing block 40) and fluid passageway 581 of a second housing portion 542 (e.g., the manifold 42). An elastomeric member 580 (e.g., O-ring) may be placed between the first housing portion 540 and the second housing portion 542 to provide a fluid tight seal at the interface between the first housing portion 540 and the second housing portion 542. For example, the elastomeric member 580 may be positioned in a channel 541 of the first housing portion 540 and/or in a channel 543 of the second housing portion 542. The channel 541 of the first housing portion 540 may be aligned with the channel 543 of the second housing portion 542, sandwiching the elastomeric member 580 therebetween.

As shown in FIG. 10A, in some embodiments the first housing portion 540 and/or the second housing portion 542 may include a channel 587 for receiving a component of the valve 570. For example, the spring 586 may be positioned in the channel 587 of the first housing portion 540 and/or the elastomeric member 590 may be positioned in the channel 587 of the second housing portion 542. It is noted that if the flow of fluid is desired in the opposite direction, then the components of the valve 570 would be reversed, such that the spring 586 may be positioned in the channel 587 of the second housing portion 542 and the elastomeric member 590 may be positioned in the channel 587 of the first housing portion 540.

The channel 587 formed in the first housing portion 540 may include a bottom surface 593 and two side surfaces 591 and 592 extending from the bottom surface 593 to the surface 599 of the first housing portion 540. In some embodiments one or both of the two side surfaces 591/592 may be formed at an oblique angle to the bottom surface 593. In some embodiments, the angle between the bottom surface 593 of the channel 587 and each of the side surfaces 591/592 of the channel 587 may be an acute angle, for example. The side surfaces 591/592 may taper toward one another as the side surfaces 591/592 approach the surface 599 of the first housing portion 540, thus narrowing the channel 587 toward the surface 599 of the first housing portion 540.

As shown in FIG. 10A, in some embodiments the channel 587 of the second housing portion 542 may have a similar shape. For instance, the channel 587 formed in the second housing portion 542 may include a bottom surface 593 and two side surfaces 591 and 592 extending from the bottom surface 593 to the surface 583 of the second housing portion 542. In some embodiments one or both of the two side surfaces 591/592 may be formed at an oblique angle to the bottom surface 593. In some embodiments, the angle between the bottom surface 593 of the channel 587 and each of the side surfaces 591/592 of the channel 587 may be an acute angle, for example. The side surfaces 591/592 may taper toward one another as the side surfaces 591/592 approach the surface 583 of the second housing portion 542, thus narrowing the channel 587 toward the surface 583 of the second housing portion 542.

The elastomeric member 590 may be placed in the channel 587 of the second housing portion 542 through the opening of the channel 587 at the surface 583 of the second housing portion 542. In some embodiments, the distance across the opening of the channel 587 between the first side surface 591 and the second side surface 592 may be less than the diameter of the elastomeric member 590. The elastomeric member 590 may be slightly compressed to fit the elastomeric member 590 through the opening at the surface 583 of the second housing portion 542. However, once placed in the channel 587, the elastomeric member 590 may at least partially expand such that the elastomeric member 590 may be sufficiently retained in the channel 587. The relative sizes of the elastomeric member 590 and the distance across the opening of the channel 587 between the first side surface 591 and the second side surface 592 may inhibit the elastomeric member 590 from coming out of the channel 587.

The spring 586 of the valve 570 may be retained in the channel 587 of the first housing portion 540 and push against the poppet 584 when compressed. The spring 586 may be compressed when the first housing portion 540 is positioned adjacent the second housing portion 542. Compressive forces of the spring 586 urge the surface 585 of the poppet 584 toward the surface 583 of the second housing portion 542. When the valve 570 is closed, the poppet 584 may contact the elastomeric member 590 positioned in the channel 587 of the second housing portion 542, creating a fluid tight seal which prevents fluid from passing through the valve 570. When the valve is open, the poppet 584 may not contact the elastomeric member 590, allowing fluid to flow from the passageway 581 of the second housing portion 542, through the valve 570, and into the passageway 589 of the first housing portion 540.

The valve 570 opens and closes depending on the pressure differential across the poppet 584 of the valve 570. During operation, pressurized fluid passes through the passageway 581 of the second housing portion 542 into contact with the poppet 584. Forces generated by the pressurized fluid on the poppet 584 oppose the forces generated by the spring 586. While the forces generated by the spring 586 remain greater than the forces generated by the pressurized fluid, the surface 585 of the poppet 584 remains in contact with the elastomeric member 590. As the forces generated by the pressurized fluid on the poppet 584 exceed the forces generated by the spring 586, the poppet 584 moves away or lifts off the second housing portion 542, forming a gap between the surface 585 of the poppet 584 and the elastomeric member 590. Fluid is then allowed to pass through the gap between the poppet 584 and the second housing portion 542 in order to pass through the valve 570. When the forces of the pressurized fluid are again less than the forces generated by the spring 586, the poppet 584 moves into contact with the elastomeric member 590, eliminating the gap between the components and thus stopping the flow of fluid through the valve 570.

Alternatively, during operation a vacuum may be created in the passageway 589 of the first housing portion 540. When the vacuum exceeds a threshold level, the poppet 584 is pulled away from or lifts off of the elastomeric member 590, forming a gap between the surface 585 of the poppet 584 and the elastomeric member 590. Fluid is then drawn through the gap between the poppet 584 and the second housing portion 542 from the passageway 581 of the second housing portion 542 to the passageway 589 of the first housing portion 540.

FIGS. 11 and 12 illustrate an exemplary pumping system 100 utilizing the pump assembly 10 as described above. The pumping system 100 may include a first fluid container or reservoir 110 for holding a first fluid 111, and the pumping system 100 may include a second fluid container or reservoir 120 for holding a second fluid 121. The first fluid container 110 and/or the second fluid container 120 may be mounted onto a frame 102 of the pumping system 100. Additionally, the pump assembly 10 may be mounted onto the frame 102.

In some embodiments, the first fluid 111 may be water and the second fluid 111 may be a chemical which may be mixed with the water in order to dilute the chemical in the water. In other embodiments, the first fluid 111 may be a first chemical and the second fluid 111 may be a second chemical which may be mixed with the first chemical.

The first fluid container 110 may include a fluid outlet 112, which may extend from the bottom of the first fluid container 110, or from another area of the first fluid container 110. Similarly, the second fluid container 120 may include a fluid outlet 122, which may extend from the bottom of the second fluid container 120, or from another area of the second fluid container 120.

Additionally, in some embodiments, the first fluid container 110 may include a flow valve 138, such as a float valve, which controls the level of the first fluid 111 in the first container 110. As the fluid level in the first container 110 is lowered sufficiently, the flow valve 138 is triggered, allowing to an additional quantity of the first fluid 111 to enter the first fluid container 110 until a desired level of the first fluid 111 is attained. Thus, the flow valve 138 may ensure that a sufficient quantity of the first fluid 111 is maintained in the first fluid container 110 during operation. Similarly, in some embodiments a flow valve may be used to ensure that a sufficient quantity of the second fluid 121 is maintained in the second fluid container 120 during operation.

A first one-way check valve 152 may be placed on the fluid outlet side of the first pump 12 and a second one-way check valve 154 may be placed on the fluid outlet side of the second pump 14. The one-way check valves 152/154 may prevent fluid from reentering the pumps 12/14 from the outlet side of the pump 12/14 after being expelled from the pump 12/14 during operation.

In addition to the first fluid container 110, the second fluid container 120 and the pump assembly 10, the pumping system 100 may include one or more additional components. For example, the pumping system 100 may include a flow meter 130 for indicating the fluid flow through the first pump 12 and/or the second pump 14 of the pump assembly 10. For instance, the flow meter 130 may include a first gauge 132 to measure the flow of the first fluid 111 through the pumping system 100, and the flow meter 130 may include a second gauge 134 to measure the flow of the second fluid 121 through the pumping system 100.

Additionally, the pumping system 100 may include a first regulator 140 and a second regulator 142. The first regulator 140 may control fluid flow and/or pressure of the first fluid 111 through the pumping system 100, and the second regulator 142 may control fluid flow and/or pressure of the second fluid 121 through the pumping system 100. The first and second regulators 140/142 of the pumping system 100 are shown as pressure regulators.

It is noted that hoses, pipes and other fluid conduits have been removed from the pumping system 100 shown in FIG. 11 in order to preserve the clarity of the figure. One of skill in the art, in view of the schematic depiction of the pumping system 100, would appreciate that various components of the pumping system 100 may be fluidly coupled together using hoses, pipes and/or fluid conduits extending between a fluid outlet of a first component to a fluid inlet of a second component.

FIG. 13 is a schematic depiction of the pumping system 100 of FIGS. 11 and 12 showing various components of the pumping system 100 fluidly connected. In describing the various components as being fluidly connected, what is meant is that hoses, pipes or other fluid conduits may be used to place the various components in fluid communication with one or more other components of the pumping system 100.

As shown in FIG. 13, the outlet 112 of the first fluid container 110 may be fluidly connected to the first inlet 113 a of the first pump 12. The second outlet 114 b of the first pump 12 may be fluidly connected with a fluid applicator 180, such as a spray gun, nozzle, boom, or the like. The first outlet 114 a of the first pump 12 may be fluidly connected to the inlet 115 of the regulator 140, and the outlet 116 of the regulator 140 may be fluidly connected to the inlet 117 of the flow meter 130. The outlet 118 of the flow meter 130 may be fluidly connected to an inlet 119 of the first fluid container 110.

Thus, during operation the pump 12 will draw the first fluid 111 from the first fluid container 110 into the pump 12. The pump 12 will pump the first fluid 111 out of the pump 12 either through the first outlet 114 a or the second outlet 114 b of the pump 12. The pressure regulator 140 may control which of the first outlet 114 a or the second outlet 114 b of the pump 12 the first fluid 111 is pumped through.

The pressure regulator 140, which may be an adjustable pressure regulator or a pre-set or non-adjustable pressure regulator, may be set to a threshold pressure. At pressures below the threshold pressure, the pressure regulator 140 does not allow fluid flow through from the inlet 115 of the pressure regulator 140 to the outlet 116 of the pressure regulator 140. Thus, at pressures below the threshold pressure, the first fluid 111 is expelled from the second outlet 114 b of the pump 12, across the check valve 152, into the first fluid flow line 160, into the fluid mix line or proportioned output 161, and to the applicator 180. At pressures above the threshold pressure of the pressure regulator 140, the first fluid 111 is expelled from the first outlet 114 a of the pump 12 through the first fluid bypass line 162. The first fluid bypass line 162 routes the first fluid 111 out the first outlet 114 a of the pump 12, through the pressure regulator 140, through the flow meter 130 and back to the first fluid container 110.

Thus, it can be seen that when no fluid flow is experienced or called for at the applicator 180, the first fluid 111 pumped through the first pump 12 is routed through the first fluid bypass line 162 and back to the first fluid container 110. However, when fluid flow is experienced or called for at the applicator 180, the first fluid 111 pumped through the first pump 12 is routed through the first fluid line 160 to the applicator 180. When no fluid flow is allowed across the applicator 180, the pressure at the outlet of the first pump 12 will increase until the pressure reaches the threshold pressure set at the pressure regulator 140, at which time the pressure regulator 140 will open, allowing bypass flow of the first fluid 111 pumped through the first pump 12 to be recirculated back to the first fluid container 110.

Bypass flow of the first fluid 111 back to the first fluid container 110 may also pass through the flow meter 130. The flow meter 130 may provide a visual indication of the flow rate of the first fluid 111 being pumped through the first pump 12.

Furthermore, the outlet 122 of the second fluid container 120 may be fluidly connected to the first inlet 123 a of the second pump 14. The second outlet 124 b of the second pump 14 may be fluidly connected with the fluid applicator 180. The first outlet 124 a of the second pump 14 may be fluidly connected to the inlet 125 of the regulator 142, and the outlet 126 of the regulator 142 may be fluidly connected to the inlet 127 of the flow meter 130. The outlet 128 of the flow meter 130 may be fluidly connected to an inlet 129 of the second fluid container 120.

Thus, during operation the pump 14 will draw the second fluid 121 from the second fluid container 120 into the pump 14. The pump 14 will pump the second fluid 121 out of the pump 14 either through the first outlet 124 a or the second outlet 124 b of the pump 14. The pressure regulator 142 may control which of the first outlet 124 a or the second outlet 124 b of the pump 14 the second fluid 121 is pumped through.

The pressure regulator 142, which may be an adjustable pressure regulator or a pre-set or non-adjustable pressure regulator, may be set to a threshold pressure. At pressures below the threshold pressure, the pressure regulator 142 does not allow fluid flow through from the inlet 125 of the pressure regulator 142 to the outlet 126 of the pressure regulator 142. Thus, at pressures below the threshold pressure, the second fluid 121 is expelled from the second outlet 124 b of the pump 14, across the check valve 154, into the second fluid flow line 163, into the fluid mix line or proportioned output 161, and to the applicator 180. At pressures above the threshold pressure of the pressure regulator 142, the second fluid 121 is expelled from the first outlet 124 a of the pump 14 through the second fluid bypass line 164. The second fluid bypass line 164 routes the second fluid 121 out the first outlet 124 a of the pump 14, through the pressure regulator 142, through the flow meter 130 and back to the second fluid container 120.

Thus, it can be seen that when no fluid flow is experienced or called for at the applicator 180, the second fluid 121 pumped through the second pump 14 is routed through the second fluid bypass line 164 and back to the second fluid container 120. However, when fluid flow is experienced or called for at the applicator 180, the second fluid 121 pumped through the second pump 14 is routed through the second fluid flow line 163 to the applicator 180. When no fluid flow is allowed across the applicator 180, the pressure at the outlet of the second pump 14 will increase until the pressure reaches the threshold pressure set at the pressure regulator 142, at which time the pressure regulator 142 will open, allowing bypass flow of the second fluid 121 pumped through the second pump 14 to be recirculated back to the second fluid container 120.

Bypass flow of the second fluid 121 back to the second fluid container 120 may also pass through the flow meter 130. The flow meter 130 may provide a visual indication of the flow rate of the second fluid 121 being pumped through the second pump 14. Thus, the flow meter 130 may provide a visual indication of the flow rates of both the first fluid 111 and the second fluid 121 through the pumping system 100. The flow rate of the first fluid 111 may be compared with the flow rate of the second fluid 121 to ensure that the proper fluid mix is achieved at the applicator 180 of the pumping system 100.

During operation, the electric motor 22 of the pump assembly 10 may drive each of the first pump 12 and the second pump 14. The transmission 30 may deliver rotational power to the second pump 14 through the second drive shaft 34 (see FIG. 2) at the same rate or at a different rate than rotational power is delivered to the first pump 12 through the first drive shaft 24 (see FIG. 2). Thus, the first pump 12 may be driven at a first rate and the second pump 14 may be driven at a second rate. In embodiments in which the displacement of each of the pumps 12/14 is the same, when the first pump 12 is driven at a first rate and the second pump is driven at a second rate different from the first rate, then the flow rate of the output of the first fluid 111 from the first pump 12 is different than the flow rate of the output of the second fluid 121 from the second pump 14.

Therefore, the first fluid 111 may be pumped to the fluid mix line or proportioned output 161 at a first rate and the second fluid 121 may be pumped to the fluid mix line or proportioned output 161 at a second rate. Depending on the relative rates in which the first and second pumps 12/14 are driven and/or the displacements of the first and second pumps 12/14, the first fluid 111 may be pumped to the proportioned output 161 at a greater rate, the same rate, or a lesser rate than the second fluid 121 is pumped to the proportioned output 161.

In some embodiments, the desired proportions of the first fluid 111 and/or the second fluid 121 to the proportioned output 161 are not adjustable without removing and/or replacing one or more components of the pumping system 100. For example, the displacement of one or more of the first pump 12 and the second pump 14 may be altered by replacing the piston 44 with a piston of a different diameter or by replacing the cam 52 with a cam having a different eccentricity to alter the stroke length of the piston 44. In some embodiments one or more of the first pump 12 and the second pump 14 may be substituted with a pump having a different displacement. In some embodiments the transmission 30 may be changed to provide a different ratio between the rotational speed of the input (e.g., the first drive shaft 24) and the rotational speed of the output (e.g., the second drive shaft 34) of the transmission 30.

The first fluid 111 may be mixed with the second fluid 121 in the fluid mix line or proportioned output 161 prior to reaching the applicator 180. As the appropriate and desired proportions of the first fluid 111 and the second fluid 121 are delivered to the applicator 180 by the pump assembly 10, the fluid mixture maintains the desired ratio of the first fluid 111 to the second fluid 121, relatively independently of pressure and flow rate at the output.

Additionally, the first fluid 111 is only mixed with the second fluid 121 as needed. Thus, a surplus of the fluid mixture is not created, reducing waste at the conclusion of a fluid application. Furthermore, the accuracy of the ratio of the first fluid 111 to the second fluid 121 in the fluid mixture is maintained.

FIG. 14 illustrates another exemplary pumping system 200 utilizing the pumping assembly 10 as described above. The pumping system 200 may include a first fluid container or reservoir 210 for holding a first fluid 211, and the pumping system 200 may include a second fluid container or reservoir 220 for holding a second fluid 221.

The first fluid container 210 may include a fluid outlet 212, which may extend from the bottom of the first fluid container 210, or other area of the first fluid container 210. Similarly, the second fluid container 220 may include a fluid outlet 222, which may extend from the bottom of the second fluid container 220, or other area of the second fluid container 220.

Similar to the pumping system 100 shown in FIGS. 11 and 12, in some embodiments, the first fluid container 210 may be located at a position above the first pump 12 and/or the second fluid container 220 may be located at a position above the second pump 14. Such a configuration benefits in the ability of utilizing gravity to aid in self-priming of the pumps 12/14 prior to use. In other words, gravity may draw the first fluid 211 into the first pump 12 and/or gravity may draw the second fluid 221 into the second pump 14 in order to self-prime the pumps 12/14.

Additionally and/or alternatively, in embodiments in which the first fluid container 210 is located at a position above the first pump 12 and/or in embodiments in which the second fluid container 220 is located at a position above the second pump 14, any air bubbles generated at the pumps 12/14 or otherwise in the system may naturally migrate upward toward the containers 210/220 and away from the pumps 12/14. Such embodiments may help ensure that air potentially trapped in the system will not adversely affect fluid flow through the pumps 12/14, and thus will ensure that a controlled quantity of fluid is pumped through the pumps 12/14 with each stroke of the pumps 12/14.

A first one-way check valve 252 may be placed on the fluid outlet side of the first pump 12 and a second one-way check valve 254 may be placed on the fluid outlet side of the second pump 14. The one-way check valves 252/254 may prevent fluid from reentering the pumps 12/14 from the outlet side of the pump 12/14 after being expelled from the pump 12/14 during operation.

In addition to the first fluid container 210, the second fluid container 220 and the pump assembly 10, the pumping system 200 may include one or more additional components. For example, the pumping system 200 may include a first regulator 240 and a second regulator 242. The first regulator 240 may control fluid flow and/or pressure of the first fluid 211 through the pumping system 200, and the second regulator 242 may control fluid flow and/or pressure of the second fluid 221 through the pumping system 200. The first and second regulators 240/242 of the pumping system 200 are shown as pressure regulators.

It is noted that hoses, pipes and other fluid conduits have been included in the pumping system 200 shown in FIG. 14 in order to illustrate the various fluid pathways through the pumping system 200. FIG. 15 is a schematic depiction of the pumping system 200 of FIG. 14 showing various components of the pumping system 200 fluidly connected. In describing the various components as being fluidly connected, what is meant is that hoses, pipes or other fluid conduits may be used to place the various components in fluid communication with one or more other components of the pumping system 200.

As shown in FIG. 15, the outlet 212 of the first fluid container 210 may be fluidly connected to the first inlet 213 a of the first pump 12. The second outlet 214 b of the first pump 12 may be fluidly connected with a fluid applicator 280, such as a spray gun, nozzle, boom, or the like. The first outlet 214 a of the first pump 12 may be fluidly connected to the inlet 215 of the regulator 240, and the outlet 216 of the regulator 240 may be fluidly connected to an inlet 219 of the first fluid container 210.

Thus, during operation the pump 12 will draw the first fluid 211 from the first fluid container 210 into the pump 12. The pump 12 will pump the first fluid 211 out of the pump 12 either through the first outlet 214 a or the second outlet 214 b of the pump 12. The pressure regulator 240 may control which of the first outlet 214 a or the second outlet 214 b of the pump 12 the first fluid 211 is pumped through.

The pressure regulator 240, which may be an adjustable pressure regulator or a pre-set or non-adjustable pressure regulator, is set to a threshold pressure. At pressures below the threshold pressure, the pressure regulator 240 does not allow fluid flow through from the inlet 215 of the pressure regulator 240 to the outlet 216 of the pressure regulator 240. Thus, at pressures below the threshold pressure, the first fluid 211 is expelled from the second outlet 214 b of the pump 12, across the check valve 252, into the first fluid flow line 260, into the fluid mix line or proportioned output 261, and to the applicator 280. At pressures above the threshold pressure of the pressure regulator 240, the first fluid 211 is expelled from the first outlet 214 a of the pump 12 through the first fluid bypass line 262. The first fluid bypass line 262 routes the first fluid 211 out the first outlet 214 a of the pump 12, through the pressure regulator 240, and back to the first fluid container 210.

Thus, it can be seen that when no fluid flow is experienced or called for at the applicator 280, the first fluid 211 pumped through the first pump 12 is routed through the first fluid bypass line 262 and back to the first fluid container 210. However, when fluid flow is experienced or called for at the applicator 280, the first fluid 211 pumped through the first pump 12 is routed through the first fluid line 260 to the applicator 280. When no fluid flow is allowed across the applicator 280, the pressure at the outlet of the first pump 12 will increase until the pressure reaches the threshold pressure set at the pressure regulator 240, at which time the pressure regulator 240 will open, allowing bypass flow of the first fluid 211 pumped through the first pump 12 to be recirculated back to the first fluid container 210.

Furthermore, the outlet 222 of the second fluid container 220 may be fluidly connected to the first inlet 223 a of the second pump 14. The second outlet 224 b of the second pump 14 may be fluidly connected with the fluid applicator 280. The first outlet 224 a of the second pump 14 may be fluidly connected to the inlet 225 of the regulator 242, and the outlet 226 of the regulator 242 may be fluidly connected to an inlet 229 of the second fluid container 220.

Thus, during operation the pump 14 will draw the second fluid 221 from the second fluid container 220 into the pump 14. The pump 14 will pump the second fluid 221 out of the pump 14 either through the first outlet 224 a or the second outlet 224 b of the pump 14. The pressure regulator 242 may control which of the first outlet 224 a or the second outlet 224 b of the pump 14 the second fluid 221 is pumped through.

The pressure regulator 242, which may be an adjustable pressure regulator or a pre-set or non-adjustable pressure regulator, is set to a threshold pressure. At pressures below the threshold pressure, the pressure regulator 242 does not allow fluid flow through from the inlet 225 of the pressure regulator 242 to the outlet 226 of the pressure regulator 242. Thus, at pressures below the threshold pressure, the second fluid 221 is expelled from the second outlet 224 b of the pump 14, across the check valve 254, into the second fluid flow line 263, into the fluid mix line or proportioned output 161, and to the applicator 280. At pressures above the threshold pressure of the pressure regulator 242, the second fluid 221 is expelled from the first outlet 224 a of the pump 14 through the second fluid bypass line 264. The second fluid bypass line 264 routes the second fluid 221 out the first outlet 224 a of the pump 14, through the pressure regulator 242, and back to the second fluid container 220.

Thus, it can be seen that when no fluid flow is experienced or called for at the applicator 280, the second fluid 221 pumped through the second pump 14 is routed through the second fluid bypass line 264 and back to the second fluid container 220. However, when fluid flow is experienced or called for at the applicator 280, the second fluid 221 pumped through the second pump 14 is routed through the second fluid flow line 263 to the applicator 280. When no fluid flow is allowed across the applicator 280, the pressure at the outlet of the second pump 14 will increase until the pressure reaches the threshold pressure set at the pressure regulator 242, at which time the pressure regulator 242 will open, allowing bypass flow of the second fluid 221 pumped through the second pump 14 to be recirculated back to the second fluid container 220.

During operation, the electric motor 22 of the pump assembly 10 may drive each of the first pump 12 and the second pump 14. The transmission 30 may deliver rotational power to the second pump 14 through the second drive shaft 34 (see FIG. 2) at the same rate or at a different rate than rotational power is delivered to the first pump 12 through the first drive shaft 24 (see FIG. 2). Thus, the first pump 12 may be driven at a first rate and the second pump 14 may be driven at a second rate. In embodiments in which the displacement of each of the pumps 12/14 is the same, when the first pump 12 is driven at a first rate and the second pump is driven at a second rate different from the first rate, then the flow rate of the output of the first fluid 211 from the first pump 12 is different than the flow rate of the output of the second fluid 221 from the second pump 14.

Therefore, the first fluid 211 may be pumped to the fluid mix line or proportioned output 261 at a first rate and the second fluid 221 may be pumped to the fluid mix line or proportioned output 261 at a second rate. Depending on the relative rates in which the first and second pumps 12/14 are driven and/or the displacements of the first and second pumps 12/14, the first fluid 211 may be pumped to the proportioned output 261 at a greater rate, the same rate, or a lesser rate than the second fluid 221 is pumped to the proportioned output 261.

In some embodiments, the desired proportions of the first fluid 211 and/or the second fluid 221 to the proportioned output 261 are not adjustable without removing and/or replacing one or more components of the pumping system 200. For example, the displacement of one or more of the first pump 12 and the second pump 14 may be altered by replacing the piston 44 with a piston of a different diameter or by replacing the cam 52 with a cam having a different eccentricity to alter the stroke length of the piston 44. In some embodiments one or more of the first pump 12 and the second pump 14 may be substituted with a pump having a different displacement. In some embodiments the transmission 30 may be changed to provide a different ratio between the rotational speed of the input (e.g., the first drive shaft 24) and the rotational speed of the output (e.g., the second drive shaft 34) of the transmission 30.

The first fluid 211 may be mixed with the second fluid 221 in the fluid mix line or proportioned output 261 prior to reaching the applicator 280. As the appropriate and desired proportions of the first fluid 211 and the second fluid 221 are delivered to the applicator 280 by the pump assembly 10, the fluid mixture maintains the desired ratio of the first fluid 211 to the second fluid 221.

Additionally, the first fluid 211 is only mixed with the second fluid 221 as needed. Thus, a surplus of the fluid mixture is not created, reducing waste at the conclusion of a fluid application. Furthermore, the accuracy of the ratio of the first fluid 211 to the second fluid 221 in the fluid mixture is maintained.

FIG. 16 is a schematic depiction of another pumping system 300 utilizing a plurality of the pumping assemblies 10 as described above. The pumping system 300 is a dual stage pumping system including a first stage pumping subsystem 301 and a second stage pumping subsystem 302. The first stage pumping subsystem 301 may include a first pump assembly 10 a including a first pump 12 a and a second pump 14 a. The second stage pumping subsystem 302 may include a second pump assembly 10 b including a third pump 12 b and a fourth pump 14 b.

The first stage pumping subsystem 301 may include a first fluid container or reservoir 310 for holding a first fluid 311, and the first stage pumping subsystem 301 may include a second fluid container or reservoir 320 for holding a second fluid 321.

As shown in FIG. 16, the outlet 312 of the first fluid container 310 may be fluidly connected to the first inlet 313 a of the first pump 12 a. The second outlet 314 b of the first pump 12 a may be fluidly connected with a first stage output 361 of the first pumping subsystem 301. The first outlet 314 a of the first pump 12 a may be fluidly connected to an inlet 319 of the first container 310 via a first fluid bypass line 362. It is noted that, although not shown in FIG. 16, a recirculating valve assembly, which may include a pressure regulator similar to the pressure regulator described above regarding the pumping systems 100/200, may be placed in the first fluid bypass line 362 as desired.

Thus, during operation the first pump 12 a will draw the first fluid 311 from the first fluid container 310 into the first pump 12 a. The first pump 12 a will pump the first fluid 311 out of the pump 12 a either through the first outlet 314 a or the second outlet 314 b of the pump 12 a. In some embodiments, a recirculating valve assembly may control which of the first outlet 314 a or the second outlet 314 b of the first pump 12 a the first fluid 311 is pumped through.

When the first fluid 311 is pumped out of the first outlet 314 a of the first pump 12 a, the first fluid 311 may be recirculated back to the first fluid container 310. When the first fluid 311 is pumped out of the second outlet 314 b of the first pump 12 a, the first fluid 311 may be pumped through a one-way check valve 352 located in a first fluid output line 360 to the first stage output 361. The check valve 352 may prevent fluid from reentering the pump 12 a from the outlet side of the pump 12 a after being expelled from the pump 12 a during operation.

Additionally, the outlet 322 of the second fluid container 320 may be fluidly connected to the first inlet 323 a of the second pump 14 a. The second outlet 324 b of the second pump 14 a may be fluidly connected with the first stage output 361 of the first pumping subsystem 301. The first outlet 324 a of the second pump 14 a may be fluidly connected to an inlet 329 of the second container 320 via a second fluid bypass line 364. It is noted that, although not shown in FIG. 16, a recirculating valve assembly, which may include a pressure regulator similar to the pressure regulator described above regarding the pumping systems 100/200, may be placed in the second fluid bypass line 364 as desired.

Thus, during operation the second pump 14 a will draw the second fluid 321 from the second fluid container 320 into the second pump 14 a. The second pump 14 a will pump the second fluid 321 out of the pump 14 a either through the first outlet 324 a or the second outlet 324 b of the pump 14 a. In some embodiments, a recirculating valve assembly may control which of the first outlet 324 a or the second outlet 324 b of the second pump 14 a the second fluid 321 is pumped through.

When the second fluid 321 is pumped out of the first outlet 324 a of the second pump 14 a, the second fluid 321 may be recirculated back to the second fluid container 320. When the second fluid 321 is pumped out of the second outlet 324 b of the second pump 14 a, the second fluid 321 may be pumped through a one-way check valve 354 located in a second fluid output line 363 to the first stage output 361. The check valve 354 may prevent fluid from reentering the pump 14 a from the outlet side of the pump 14 a after being expelled from the pump 14 a during operation.

During operation, the electric motor 22 a of the pump assembly 10 a may drive each of the first pump 12 a and the second pump 14 a. The transmission 30 a may deliver rotational power to the second pump 14 a through the second drive shaft 34 (see FIG. 2) at the same rate or at a different rate than rotational power is delivered to the first pump 12 a through the first drive shaft 24 (see FIG. 2). Thus, the first pump 12 a may be driven at a first rate and the second pump 14 a may be driven at a second rate. In embodiments in which the displacement of each of the pumps 12 a/14 a is the same, when the first pump 12 a is driven at a first rate and the second pump 14 a is driven at a second rate different from the first rate, then the flow rate of the output of the first fluid 311 from the first pump 12 a is different than the flow rate of the output of the second fluid 321 from the second pump 14 a.

Therefore, the first fluid 311 may be pumped to the first stage outlet 361 at a first rate and the second fluid 321 may be pumped to the first stage outlet 361 at a second rate. Depending on the relative rates in which the first and second pumps 12 a/14 a are driven and/or the displacements of the first and second pumps 12 a/14 a, the first fluid 311 may be pumped to the first stage output 361 at a greater rate, the same rate, or a lesser rate than the second fluid 321 is pumped to the first stage output 361.

In some embodiments, the desired proportions of the first fluid 311 and/or the second fluid 321 to the first stage output 361 are not adjustable without removing and/or replacing one or more components of the pumping subsystem 301. For example, the displacement of one or more of the first pump 12 a and the second pump 14 a may be altered by replacing the piston 44 with a piston of a different diameter or by replacing the cam 52 with a cam having a different eccentricity to alter the stroke length of the piston 44. In some embodiments one or more of the first pump 12 a and the second pump 14 a may be substituted with a pump having a different displacement. In some embodiments the transmission 30 a may be changed to provide a different ratio between the rotational speed of the input (e.g., the first drive shaft 24) and the rotational speed of the output (e.g., the second drive shaft 34) of the transmission 30.

The first fluid 311 may be mixed with the second fluid 321 in the first stage output 361. As the appropriate and desired proportions of the first fluid 311 and the second fluid 321 are delivered to the first stage output 361 by the pump assembly 10 a, the fluid mixture maintains the desired ratio of the first fluid 311 to the second fluid 321, relatively independently of pressure and flow rate at the output.

Additionally, the first fluid 311 is only mixed with the second fluid 321 as needed. Thus, a surplus of the fluid mixture is not created, reducing waste at the conclusion of a fluid application. Furthermore, the accuracy of the ratio of the first fluid 311 to the second fluid 321 in the fluid mixture is maintained.

Thus, the first stage output 361 includes a proportioned fluid mix of the first fluid 311 and the second fluid 321 at a desired ratio. The first stage output 361 may be connected to an inlet of the second stage pumping subsystem 302, such as a first stage mix container 380.

The second stage pumping subsystem 302 may include a first stage mix container or reservoir 380 for holding a first stage fluid mixture 381 of the first fluid 311 and the second fluid 321 output from the first stage pumping subsystem 301 through the first stage output 361, and the second stage pumping subsystem 302 may include a third fluid container or reservoir 390 for holding a third fluid 391.

As shown in FIG. 16, the outlet 382 of the first stage mixed fluid container 380 may be fluidly connected to the first inlet 383 a of the third pump 12 b. The second outlet 384 b of the third pump 12 b may be fluidly connected with a fluid applicator 370, such as a spray gun, nozzle, boom, or the like through the second stage outlet 398. The first outlet 384 a of the third pump 12 b may be fluidly connected to an inlet 389 of the first stage mixed fluid container 380 via a first stage mixed fluid bypass line 385. It is noted that, although not shown in FIG. 16, a recirculating valve assembly, which may include a pressure regulator similar to the pressure regulator described above regarding the pumping systems 100/200, may be placed in the first stage mixed fluid bypass line 385 as desired.

Thus, during operation the third pump 12 b will draw the first stage fluid mixture 381 from the first stage mixed fluid container 380 into the third pump 12 b. The third pump 12 b will pump the first stage fluid mixture 381 out of the pump 12 b either through the first outlet 384 a or the second outlet 384 b of the pump 12 b. In some embodiments, a recirculating valve assembly may control which of the first outlet 384 a or the second outlet 384 b of the third pump 12 b the first stage fluid mixture 381 is pumped through.

When the first stage fluid mixture 381 is pumped out of the first outlet 384 a of the third pump 12 b, the first stage fluid mixture 381 may be recirculated back to the first stage mixed fluid container 380. When the first stage fluid mixture 381 is pumped out of the second outlet 384 b of the third pump 12 b, the first stage fluid mixture 381 may be pumped through a one-way check valve 353 located in a first stage fluid mixture output line 386 to the second stage output 398. The check valve 353 may prevent fluid from reentering the pump 12 b from the outlet side of the pump 12 b after being expelled from the pump 12 b during operation.

Additionally, the outlet 392 of the third fluid container 390 may be fluidly connected to the first inlet 393 a of the fourth pump 14 b. The second outlet 394 b of the fourth pump 14 b may be fluidly connected with the fluid applicator 370. The first outlet 394 a of the fourth pump 14 b may be fluidly connected to an inlet 399 of the third fluid container 390 via a third fluid bypass line 395. It is noted that, although not shown in FIG. 16, a recirculating valve assembly, which may include a pressure regulator similar to the pressure regulator described above regarding the pumping systems 100/200, may be placed in the third fluid bypass line 395 as desired.

Thus, during operation the fourth pump 14 b will draw the third fluid 391 from the third fluid container 390 into the fourth pump 14 b. The fourth pump 14 b will pump the third fluid 391 out of the pump 14 b either through the first outlet 394 a or the second outlet 394 b of the pump 14 b. In some embodiments, a recirculating valve assembly may control which of the first outlet 394 a or the second outlet 394 b of the fourth pump 14 b the third fluid 391 is pumped through.

When the third fluid 391 is pumped out of the first outlet 394 a of the fourth pump 14 b, the third fluid 391 may be recirculated back to the third fluid container 390. When the third fluid 391 is pumped out of the second outlet 394 b of the fourth pump 14 b, the third fluid 391 may be pumped through a one-way check valve 355 located in a third fluid output line 396 to the fluid applicator 370 through the second stage output 398. The check valve 355 may prevent fluid from reentering the pump 14 b from the outlet side of the pump 14 b after being expelled from the pump 14 b during operation.

During operation, the electric motor 22 b of the pump assembly 10 b may drive each of the third pump 12 b and the fourth pump 14 b. The transmission 30 b may deliver rotational power to the fourth pump 14 b through the second drive shaft 34 (see FIG. 2) at the same rate or at a different rate than rotational power is delivered to the third pump 12 b through the first drive shaft 24 (see FIG. 2). Thus, the third pump 12 b may be driven at a first rate and the fourth pump 14 b may be driven at a second rate. In embodiments in which the displacement of each of the pumps 12 b/14 b is the same, when the third pump 12 b is driven at a first rate and the fourth pump 14 b is driven at a second rate different from the first rate, then the flow rate of the output of the first stage fluid mixture 381 from the third pump 12 b is different than the flow rate of the output of the fourth fluid 391 from the fourth pump 14 b.

Therefore, the first stage fluid mixture 381 may be pumped to the second stage output 398 and out to the fluid applicator 370 at a first rate and the third fluid 391 may be pumped to the second stage output 398 and out to the fluid applicator 370 at a second rate. Depending on the relative rates in which the third and fourth pumps 12 b/14 b are driven and/or the displacements of the third and fourth pumps 12 b/14 b, the first stage fluid mixture 381 may be pumped to the second stage output 398 and out to the fluid applicator 370 at a greater rate, the same rate, or a lesser rate than the third fluid 391 is pumped to the second stage output 398 and out to the fluid applicator 370.

In some embodiments, the desired proportions of the first stage fluid mixture 381 and/or the third fluid 391 to the second stage output 398 and out to the fluid applicator 370 are not adjustable without removing and/or replacing one or more components of the pumping subsystem 302. For example, the displacement of one or more of the third pump 12 b and the fourth pump 14 b may be altered by replacing the piston 44 with a piston of a different diameter or by replacing the cam 52 with a cam having a different eccentricity to alter the stroke length of the piston 44. In some embodiments one or more of the third pump 12 b and the fourth pump 14 b may be substituted with a pump having a different displacement. In some embodiments the transmission 30 b may be changed to provide a different ratio between the rotational speed of the input (e.g., the first drive shaft 24) and the rotational speed of the output (e.g., the second drive shaft 34) of the transmission 30 b.

The first stage fluid mixture 381, which is a proportioned mixture of the first fluid 311 and the second fluid 321, may be mixed with the third fluid 391 in the second stage output 398. As the appropriate and desired proportions of the first fluid 311 and the second fluid 321 are delivered to the first stage output 361 by the pump assembly 10 a, and the appropriate and desired proportions of the third fluid 391 and the first stage fluid mixture 381 of the first fluid 311 and the second fluid 321 are delivered to the second stage output 398, the pumping system 300 maintains the desired ratio of the first fluid 311, the second fluid 321 and the third fluid 391 at the second stage output 398 to the fluid applicator 370.

Additionally, the first fluid 311, the second fluid 321 and the third fluid 391 are only mixed as needed. Thus, a surplus of the fluid mixture is not created, reducing waste at the conclusion of a fluid application. Furthermore, the accuracy of the ratio of the first fluid 311, the second fluid 321 and the third fluid 391 in the fluid mixture is maintained.

In addition to the first fluid container 310, the second fluid container 320, the first stage mix container 380, the third fluid container 390 and the pump assemblies 10 a/10 b, the pumping system 300 may include one or more additional components. For example, the pumping system 300 may include one or more flow meters for indicating the fluid flow through one or more of the pumps of one or more of the pump assemblies 10 a/10 b. For instance, in some embodiments one or more flow meters may be included in the pumping system 300 similar to the flow meter 130 of the pumping system 100.

Additionally, the pumping system 300 may include one or more regulators which may control fluid flow and/or pressure of one or more fluids and/or fluid mixes through the pumping system 300. For instance, in some embodiments a flow regulator and/or a pressure regulator may be included in the pumping system 300 similar to the pressure regulator 140/142 of the pumping system 100.

It is noted that one of skill in the art, in view of the schematic depiction of the pumping system 300, would appreciate that various components of the pumping system 300 may be fluidly coupled together using hoses, pipes and/or fluid conduits extending between a fluid outlet of a first component to a fluid inlet of a second component.

Additional pumping subsystems may be added to the pumping system 300 to further mix a plurality of fluids. For example, a third pumping subsystem may be added in order to add a fourth fluid to the fluid mixture outlet by the pumping system 300. Thus, it can be seen that modifications of the pumping system 300 may result in four, five, six or more fluids being mixed together in precisely and accurately specified proportions.

FIG. 17 is a schematic depiction of another pumping system 400 utilizing a plurality of the pumping assemblies 10 as described above. The pumping system 400 is a dual stage pumping system including a first stage pumping subsystem 401 and a second stage pumping subsystem 402. The first stage pumping subsystem 401 may include a first pump assembly 10 a including a first pump 12 a and a second pump 14 a. The second stage pumping subsystem 402 may include a second pump assembly 10 b including a third pump 12 b and a fourth pump 14 b.

The first stage pumping subsystem 401 may include a first fluid container or reservoir 410 for holding a first fluid 411, and the first stage pumping subsystem 401 may include a second fluid container or reservoir 420 for holding a second fluid 421.

As shown in FIG. 17, the outlet 412 of the first fluid container 410 may be fluidly connected to the first inlet 413 a of the first pump 12 a. The outlet 414 of the first pump 12 a may be fluidly connected with a first stage outlet 461 of the first pumping subsystem 401. It is noted that, although not shown in FIG. 17, a recirculating valve assembly, which may include a fluid bypass line and/or pressure regulator similar to the fluid bypass line and pressure regulator described above regarding the pumping systems 100/200, may be in fluid communication with a second outlet of the first pump 12 a and the first fluid container 410.

Thus, during operation the first pump 12 a will draw the first fluid 411 from the first fluid container 410 into the first pump 12 a. The first pump 12 a will pump the first fluid 411 out of the pump 12 a through the outlet 414 of the pump 12 a. In some embodiments, a recirculating valve assembly may control when the first fluid 411 is pumped through the outlet 414 of the first pump 12 a.

When the first fluid 411 is pumped out of the outlet 414 of the first pump 12 a, the first fluid 411 may be pumped through a one-way check valve 452 located in a first fluid output line 460 to the first stage proportioned output 461. The check valve 452 may prevent fluid from reentering the pump 12 a from the outlet side of the pump 12 a after being expelled from the pump 12 a during operation.

Additionally, the outlet 422 of the second fluid container 420 may be fluidly connected to the inlet 423 of the second pump 14 a. The outlet 424 of the second pump 14 a may be fluidly connected with the first stage outlet 461 of the first pumping subsystem 401. It is noted that, although not shown in FIG. 17, a recirculating valve assembly, which may include a fluid bypass line and/or pressure regulator similar to the fluid bypass line and pressure regulator described above regarding the pumping systems 100/200, may be in fluid communication with a second outlet of the second pump 14 a and the second fluid container 420.

Thus, during operation the second pump 14 a will draw the second fluid 421 from the second fluid container 420 into the second pump 14 a. The second pump 14 a will pump the second fluid 421 out of the pump 14 a through the outlet 424 of the pump 14 a. In some embodiments, a recirculating valve assembly may control when the second fluid 421 is pumped through the outlet 424 of the second pump 14 a.

When the second fluid 421 is pumped out of the outlet 424 of the second pump 14 a, the second fluid 421 may be pumped through a one-way check valve 454 located in a second fluid output line 463 to the first stage proportioned output 461. The check valve 454 may prevent fluid from reentering the pump 14 a from the outlet side of the pump 14 a after being expelled from the pump 14 a during operation.

During operation, the electric motor 22 a of the pump assembly 10 a may drive each of the first pump 12 a and the second pump 14 a. The transmission 30 a may deliver rotational power to the second pump 14 a through the second drive shaft 34 (see FIG. 2) at the same rate or at a different rate than rotational power is delivered to the first pump 12 a through the first drive shaft 24 (see FIG. 2). Thus, the first pump 12 a may be driven at a first rate and the second pump 14 a may be driven at a second rate. In embodiments in which the displacement of each of the pumps 12 a/14 a is the same, when the first pump 12 a is driven at a first rate and the second pump 14 a is driven at a second rate different from the first rate, then the flow rate of the output of the first fluid 411 from the first pump 12 a is different than the flow rate of the output of the second fluid 421 from the second pump 14 a.

Therefore, the first fluid 411 may be pumped to the first stage proportioned output 461 at a first rate and the second fluid 421 may be pumped to the first stage proportioned output 461 at a second rate. Depending on the relative rates in which the first and second pumps 12 a/14 a are driven and/or the displacements of the first and second pumps 12 a/14 a, the first fluid 411 may be pumped to the first stage proportioned output 461 at a greater rate, the same rate, or a lesser rate than the second fluid 421 is pumped to the first stage proportioned output 461.

In some embodiments, the desired proportions of the first fluid 411 and/or the second fluid 421 to the first stage proportioned output 461 are not adjustable without removing and/or replacing one or more components of the pumping subsystem 401. For example, the displacement of one or more of the first pump 12 a and the second pump 14 a may be altered by replacing the piston 44 with a piston of a different diameter or by replacing the cam 52 with a cam having a different eccentricity to alter the stroke length of the piston 44. In some embodiments one or more of the first pump 12 a and the second pump 14 a may be substituted with a pump having a different displacement. In some embodiments the transmission 30 a may be changed to provide a different ratio between the rotational speed of the input (e.g., the first drive shaft 24) and the rotational speed of the output (e.g., the second drive shaft 34) of the transmission 30 a.

The first fluid 411 may be mixed with the second fluid 421 in the first stage proportioned output 461. As the appropriate and desired proportions of the first fluid 411 and the second fluid 421 are delivered to the first stage proportioned output 461 by the pump assembly 10 a, the fluid mixture maintains the desired ratio of the first fluid 411 to the second fluid 421, relatively independently of pressure and flow rate at the output.

Thus, the first stage proportioned output 461 includes a proportioned fluid mix of the first fluid 411 and the second fluid 421 at a desired ratio. The first stage output 461 may be connected to an inlet of the second stage pumping subsystem 402, such as a pump of the second stage pumping subsystem 402 or a first stage mixed fluid container (not shown).

The second stage pumping subsystem 402 may include a pump assembly 10 b including a third pump 12 b and a fourth pump 14 b. As shown in FIG. 17, the outlet 412 of the first fluid container 410, or another outlet of the first fluid container 410 may be fluidly connected to the inlet 483 of the third pump 12 b. The outlet 484 of the third pump 12 b may be fluidly connected with a fluid applicator 470, such as a spray gun, nozzle, boom, or the like through the second stage proportioned output 498.

Thus, during operation the third pump 12 b will draw the first fluid 411 from the first fluid container 410 into the third pump 12 b. The third pump 12 b will pump the first fluid 411 out of the pump 12 b through the outlet 484 of the pump 12 b. In some embodiments, a recirculating valve assembly may control when the first fluid 411 is pumped through the outlet 484 of the third pump 12 b.

When the first fluid 411 is pumped out of the outlet 484 of the third pump 12 b, the first fluid 411 may be pumped through a one-way check valve 453 located in a first fluid outlet line 486 to the second stage proportioned output 498. The check valve 453 may prevent fluid from reentering the pump 12 b from the outlet side of the pump 12 b after being expelled from the pump 12 b during operation.

Additionally, the first stage proportioned output 461 of the first pumping subsystem 401 may be fluidly connected to the inlet 493 of the fourth pump 14 b. The outlet 494 of the fourth pump 14 b may be fluidly connected with the fluid applicator 470 through the second stage proportioned output 498. It is noted that, although not shown in FIG. 17, a recirculating valve assembly, which may include a fluid bypass line and/or pressure regulator similar to the fluid bypass line and pressure regulator described above regarding the pumping systems 100/200, may be in fluid communication with a second outlet of the fourth pump 14 b, as desired.

Thus, during operation the fourth pump 14 b will draw the first stage fluid mixture 491 (e.g., a proportioned mixture of the first fluid 411 and the second fluid 421) from the first stage output 461 into the fourth pump 14 b. The fourth pump 14 b will pump the first stage fluid mixture 491 out of the pump 14 b through the outlet 494 of the pump 14 b. In some embodiments, a recirculating valve assembly may control when the first stage fluid mixture 491 is pumped through the outlet 494 of the fourth pump 14 b.

When the first stage fluid mixture 491 is pumped out of the outlet 494 of the fourth pump 14 b, the first stage fluid mixture 491 may be pumped through a one-way check valve 455 located in a first stage fluid output line 496 to the fluid applicator 470 through the second stage proportioned output 498. The check valve 455 may prevent fluid from reentering the pump 14 b from the outlet side of the pump 14 b after being expelled from the pump 14 b during operation.

During operation, the electric motor 22 b of the pump assembly 10 b may drive each of the third pump 12 b and the fourth pump 14 b. The transmission 30 b may deliver rotational power to the fourth pump 14 b through the second drive shaft 34 (see FIG. 2) at the same rate or at a different rate than rotational power is delivered to the third pump 12 b through the first drive shaft 24 (see FIG. 2). Thus, the third pump 12 b may be driven at a first rate and the fourth pump 14 b may be driven at a second rate. In embodiments in which the displacement of each of the pumps 12 b/14 b is the same, when the third pump 12 b is driven at a first rate and the fourth pump 14 b is driven at a second rate different from the first rate, then the flow rate of the output of the first fluid 411 from the third pump 12 b is different than the flow rate of the output of the first stage fluid mixture 491 from the fourth pump 14 b.

Therefore, the first stage fluid mixture 491 may be pumped to the second stage proportioned output 498 and out to the fluid applicator 470 at a first rate and the first fluid 411 may be pumped to the second stage proportioned output 498 and out to the fluid applicator 470 at a second rate. Depending on the relative rates in which the third and fourth pumps 12 b/14 b are driven and/or the displacements of the third and fourth pumps 12 b/14 b, the first stage fluid mixture 491 may be pumped to the second stage proportioned output 498 and out to the fluid applicator 470 at a greater rate, the same rate, or a lesser rate than the first fluid 411 is pumped to the second stage proportioned output 498 and out to the fluid applicator 470.

In some embodiments, the desired proportions of the first stage fluid mixture 491 and/or the first fluid 411 to the second stage output 498 and out to the fluid applicator 470 are not adjustable without removing and/or replacing one or more components of the pumping subsystem 402. For example, the displacement of one or more of the third pump 12 b and the fourth pump 14 b may be altered by replacing the piston 44 with a piston of a different diameter or by replacing the cam 52 with a cam having a different eccentricity to alter the stroke length of the piston 44. In some embodiments one or more of the third pump 12 b and the fourth pump 14 b may be substituted with a pump having a different displacement. In some embodiments the transmission 30 b may be changed to provide a different ratio between the rotational speed of the input (e.g., the first drive shaft 24) and the rotational speed of the output (e.g., the second drive shaft 34) of the transmission 30 b.

The first stage fluid mixture 491, which is a proportioned mixture of the first fluid 411 and the second fluid 421, may be mixed with an additional quantity of the first fluid 411 in the second stage outlet 498. As the appropriate and desired proportions of the first fluid 411 and the second fluid 421 are delivered to the first stage output 461 by the pump assembly 10 a, and the appropriate and desired proportions of the first fluid 411 and the first stage fluid mixture 491 of the first fluid 411 and the second fluid 421 are delivered to the second stage output 498, the pumping system 400 maintains the desired ratio of the first fluid 411 and the second fluid 421 at the second stage proportioned output 498 to the fluid applicator 470. Thus, it can be demonstrated that the pumping system 400 may be beneficial in forming a mixture of the first fluid 411 and the second fluid 421 at rates in which the first fluid 411 is present in quantities much greater than the quantity of the second fluid 421. For instance, in some embodiments the pumping system may provide a mixture of the first fluid 411 and the second fluid 421 having a ratio in the range of 100:1 to 1600:1, in the range of 100:1 to 200:1, in the range of 200:1 to 400:1, in the range of 400:1 to 800:1, in the range of 500:1 to 1000:1, in the range of 800:1 to 1200:1, in the range of 1200:1 to 1400:1, in the range of 1000:1 to 1600:1. In some embodiment the ratio of the first fluid 411 to the second fluid 421 may be 100:1, 200:1, 300:1, 400:1, 500:1, 600:1, 700:1, 800:1, 900:1; 1000:1, 1296:1 or 1600:1.

Additionally, the first fluid 411 and the second fluid 421 are only mixed as needed. Thus, a surplus of the fluid mixture is not created, reducing waste at the conclusion of a fluid application. Furthermore, the accuracy of the ratio of the first fluid 411, the second fluid 421 in the fluid mixture is maintained.

In addition to the first fluid container 410, the second fluid container 420 and the pump assemblies 10 a/10 b, the pumping system 400 may include one or more additional components. For example, the pumping system 400 may include one or more flow meters for indicating the fluid flow through one or more of the pumps of one or more of the pump assemblies 10. For instance, in some embodiments one or more flow meters may be included in the pumping system 400 similar to the flow meter 130 of the pumping system 100.

Additionally, the pumping system 400 may include one or more regulators which may control fluid flow and/or pressure of one or more fluids and/or fluid mixes through the pumping system 400. For instance, in some embodiments a flow regulator and/or a pressure regulator may be included in the pumping system 400 similar to the pressure regulator 140/142 of the pumping system 100.

It is noted that one of skill in the art, in view of the schematic depiction of the pumping system 400, would appreciate that various components of the pumping system 400 may be fluidly coupled together using hoses, pipes and/or fluid conduits extending between a fluid outlet of a first component to a fluid inlet of a second component.

Additional pumping subsystems may be added to the pumping system 400 to further mix a plurality of fluids. For example, a third pumping subsystem may be added in order to further dilute the second fluid 421 in a mixture of the first fluid 411. Thus, it can be seen that modifications of the pumping system 400 may result in a plurality of fluids being mixed together in precisely and accurately specified proportions.

FIG. 18 illustrates an exemplary control system 205 incorporated with the pumping system 200 of FIG. 14. As the pumping system 200 shown in FIG. 18 is similar to that shown in FIG. 14 and described herein, a description of various components of the pumping system 200 will not be repeated. Although the control system 205 is described in association with the pumping system 200, it is noted that the control system 205 or another control system may be incorporated with another exemplary pumping system including the other exemplary pumping systems described herein.

The control system 205 may include a control box 280 and one or more switches, transducers, gauges, meters, solenoids, relays, speed controllers, flow controllers, pressure controllers, or the like. The control box 280 may include a switch, such as a master on/off switch 282, controlling electrical signals through the control box 280.

In some embodiments, the control system 205 may include a pressure switch and/or pressure transducer 284. In some embodiments, the pressure switch and/or pressure transducer 284 may be placed on a high pressure side of the first pump 12 and/or the second pump 14. For instance, the pressure switch and/or pressure transducer 284 may be placed in a fluid output line of the first pump 12 and/or in a fluid output line of the second pump 14. In FIG. 18, the pressure switch and/or pressure transducer 284 is shown in the first fluid bypass line 262, however, in other embodiments the pressure switch and/or pressure transducer 284 may be placed at another location such as in the first fluid output line 260 or in the proportioned output line 261. The pressure switch and/or pressure transducer 284 may send a signal regarding the pressure sensed by the pressure switch and/or pressure transducer 284 to the control box 280.

Additionally or alternatively, in some embodiments the control system 205 may include a flow switch and/or flow transducer 286. The flow switch and/or flow transducer 286 may be placed in a fluid output line of the first pump 12 and/or in a fluid output line of the second pump 14. In FIG. 18, the flow switch and/or flow transducer 286 is shown in the proportioned output line 261, however, in other embodiments the flow switch and/or flow transducer 286 may be placed at another location as desired. The flow switch and/or flow transducer 286 may send a signal regarding the flow sensed by the flow switch and/or flow transducer 284 to the control box 280.

In some embodiments, the control system 205 may include a speed counter/rate counter 292 which may determine the rotational rate of the first and/or second drive shaft 24/34 of the motor assembly 20 and/or the stroke rate of the first and/or second pump 12/14. As the stroke rate of the first pump 12 may be directly related to the rotational rate of the first drive shaft 24 and the stroke rate of the second pump 14 may be directly related to the rotational rate of the second drive shaft 34, sensing the speed and/or rate of one component of the system may be used to determine the speed and/or rate of another component of the system. The speed counter/rate counter 292 may send a signal regarding the speed and/or rate of a component of the system 200 to the control box 280, such as the processor 290 of the control box 280.

Additionally or alternatively, in some embodiments, the control system 205 may include a speed control module 288 for controlling the rotational rate of the first drive shaft 24 and/or the second drive shaft 34 of the motor assembly 20. For instance, in some embodiments the speed control module 288 may control the speed of the motor 22, thus controlling the rotational rate of the first drive shaft 24 and the second drive shaft 34. Thus, the speed of the motor 22 and/or the rotational rates of the first drive shaft 24 and the second drive shaft 34 may be variably controlled in some embodiments. Additionally or alternatively, in some embodiments the speed control module 288 may send a signal to the transmission 30 to control the ratio of the rotational rate of the first drive shaft 24 to the rotational rate of the second drive shaft 34. Thus, the speed of the second drive shaft 34 relative to the speed of the first drive shaft 24 may be variably controlled in some embodiments.

In some embodiments, the speed control module 288 may allow the motor 22 to run at variable speeds. Thus, the rotational rate of the first drive shaft 24 may be varied with the speed control module 288. In such embodiments, when the transmission 30 is fixed or otherwise not varied, varying the rotational rate of the first drive shaft 24 with the speed control module 288 varies the rotational rate of the second drive shaft 34 in proportion to the ratio dictated by the transmission 30. Thus, varying the speed of the motor 22 may vary the flow of fluid to the proportioned output 261 while maintaining a constant proportion of the first fluid 211 to the second fluid 221 at the proportioned output 261.

In some embodiments, the control system 205 may include a processor 290. The processor 290 may receive signals from one or more switches, transducers, counters, or other signal input devices. For example, in some embodiments the processor 290 may receive a signal from the pressure switch and/or pressure transducer 284, may receive a signal from the flow switch and/or flow transducer 286, may receive a signal from the speed counter/rate counter 292, and/or from one or more other components of the control system 205. In some embodiments, the processor 290 may transmit a signal to the speed control module 288 to control the rotational rate of the first drive shaft 24 and/or the second drive shaft 34 of the motor assembly 20.

In some embodiments, the control system 205 may include a user interface 294 which may allow an operator to input information to the processor 290. In some embodiments, the user interface 294 may include a dot-matrix display, a touch screen display, a keyboard, a curser control device such as a computer mouse or a track ball, buttons, knobs, switches, or other means of entering, selecting and/or evaluating input data. For instance, in some embodiments the user interface 294 may allow an operator to input the label dictated rate of a chemical to be mixed with water (or another fluid), input another desired rate of a chemical to be mixed with water (or another fluid) and/or select from one of a list of mix rates stored in the memory of the processor 290. Upon inputting the label dictated rate of the chemical to water, the desired rate of the chemical to water, and/or selecting a desired rate of a chemical to water, the control system 205 may control the rotational rate of the first drive shaft 24 driving the first pump 12 (dictating the flow rate of the first fluid 211) to the rotational rate of the second drive shaft 34 driving the second pump 14 (dictating the flow rate of the second fluid 221) to attain the desired or recommended rate of a fluid mixture.

In some embodiments, the user interface 294 may include a bar code scanner (not shown). In such embodiments, the user may scan the bar code of a product, such as a container of a chemical. Reading the bar code of the product, the processor 290 may be able to determine the label dictated rate recommended for the product and/or may prompt a user to select from one or more suggested rates for mixing the product (e.g., chemical) with water (or other fluid). In such embodiments, once the rate has been selected or determined, the processor 290 may send a signal to the speed control module 288 to control the rotational rate of the first drive shaft 24 and/or the rotational rate of the second drive shaft 34, and or control the relative rates of the first drive shaft 24 to the second drive shaft 34, thereby controlling the relative flow rates of fluid being pumped by the first pump 12 and the second pump 14 to the proportioned output 261 to control the ratio of the first fluid 211 to the second fluid 221 at the proportioned output 261.

The control box 280 may also include one or more gauges or meters 296, providing a visual indication of one or more operating conditions of the system 200, such as the speed of the first and/or second drive shaft 24/34 or the flow rate of the first and/or second fluid 211/221. The gauges or meters 296, or additional gauges or meters, may also be used to indicate fluid pressure, fluid concentration, amperes, voltage, etc. In some embodiments, the control system 205, including the control box 280, may include additional components such as switches, fuses, circuit breakers, solenoids, relays, gauges, meters, terminals, connectors, etc. as desired.

FIG. 19A schematically illustrates one exemplary configuration of the control system 205 used with the pumping system 200. As shown in FIG. 19A, electrical power may be provided to the speed control module 288, or other component of the control system 205, through a plurality of switches or relays 298. For instance, the on/off switch 282 may be used to control power to components of the control system 205, such as the speed control module 288 and/or the processor 290, through the switch or relay 298 a. The pressure switch 284 and/or the flow switch 286 (or relays 298 controlled by the pressure switch 284 and/or the flow switch 286) may be electrically wired in series with the on/off switch 282 to control electrical power to the speed control module 288. For instance, when the pressure switch 284 senses a pressure less than a threshold pressure, the switch or relay 298 b may close, allowing power to be passed through the switch or relay 298 b. Additionally or alternatively, when the flow switch 286 senses flow greater than a threshold flow rate (e.g., above zero flow), the switch or relay 298 c may close, allowing power to be passed through the switch or relay 298 c. Thus, as shown in FIG. 19A, when the on/off switch 282 is in the “on” position, the pressure switch 284 senses a pressure less than a threshold pressure, and the flow switch 286 senses a flow greater than a threshold flow rate, the switches or relays 298 a/298 b/298 c may be closed, allowing electrical power to pass to the speed control module 288. In other embodiments, the pressure switch 284 and the flow switch 286 may be wired in parallel, and thus, if one or the other of switches or relays 298 b or 298 c are closed, electrical power may be passed to the speed control module 288.

With the configuration illustrated in FIG. 19A, during time periods in which no fluid flow is called for at the applicator connected to the proportioned output 261, the flow switch 286 would open the relay 298 c as the detected flow (e.g., zero flow) would be below a threshold flow rate. During this time, the pressure in the first fluid bypass line 262 would increase to the threshold pressure of the pressure regulator 240. Thus, the pressure switch 284, would open the relay 298 b as the detected pressure in the first fluid bypass line 262 would be greater than a threshold pressure. As both switches or relays 298 b/298 c would be open, electrical power would not reach the speed control module 288 and the motor 22 may be stopped or disengaged to stop the pumps 12/14.

When fluid flow through the proportioned output 261 to the applicator is called for, flow through the proportioned output 261 would commence, closing the switch or relay 298 c. Additionally, commencement of flow through the proportioned output 261 would decrease the pressure in the first fluid bypass line 262 below the threshold level, closing the switch or relay 298 b. With both switches or relays 298 b/298 c closed, electrical power is transmitted to the speed control module 288 to start or engage the motor 22 to run the pumps 12/14. Placement of the pressure switch 284 in series with the flow switch 286 ensures that a signal indicating that a pressure below a threshold pressure at the pressure switch 284 is due to the presence of fluid flow through the proportioned output 261, and not due to the lack of fluid in the system 200, such as the lack of the first fluid 211 at the inlet of the first pump 12 and/or the lack of the second fluid 221 at the inlet of the second pump 14.

Additionally, signals from the user interface 294 and/or from the speed/rate counter 292 may be sent to the processor 290. For example, the current speed of the first drive shaft 24, the current speed of the second drive shaft 34, the current stroke rate of the first pump 12, and/or the current stroke rate of the second pump 14 may be sent to the processor 290. The processor 290 may process this information and may make a logic determination as to whether the rotational rate of the first drive shaft 24 and/or the second drive shaft 34 should be increased or decreased to provide a desired flow rate of a mixed fluid (at a determined mixing ratio) at the proportioned output 261. Additionally or alternatively, the processor 290 may receive a signal from the user interface 294 to control the desired rotational rate of the first drive shaft 24 and/or the second drive shaft 34. The processor 290 may send a signal to the speed control module 288 to adjust the rotational rate of the first drive shaft 24 and/or the second drive shaft 34 to attain the desired rotational rates. In some embodiments, the speed control module 288 may adjust the motor speed and/or the ratio through the transmission 30 to attain the desired rotational rates of the first drive shaft 24 (powering the first pump 12) and the second drive shaft 34 (powering the second pump 14) to attain the desired flow rate of a desired ratio of the first fluid 211 to the second fluid 221.

FIG. 19B schematically illustrates another exemplary configuration of the control system 205 used with the pumping system 200. The control box 280 may include an on/off switch 282 controlling power to the processor 290. In this configuration, signals from the pressure transducer 284 and/or the flow transducer 286 are input into the processor 290. For example, in some embodiments an analog signal may be sent to the processor 290 from the pressure transducer 284 and/or from the flow transducer 286. The processor 290 may include an analog-to-digital converter (A/D converter) to convert the inputted signals. The processor 290 may process the signals and send an output signal to the speed control module 288 to control the speed of the first drive shaft 24 and/or the second drive shaft 34 of the motor assembly 20. In some embodiments, the speed control module 288 may adjust the motor speed and/or the ratio through the transmission 30 to attain the desired rotational rates of the first drive shaft 24 (powering the first pump 12) and the second drive shaft 34 (powering the second pump 14) to attain the desired flow rate of a desired ratio of the first fluid 211 to the second fluid 221.

Thus, in such embodiments, the processor 290 (such as with a user interface 294) may call for a higher or lower flow rate at the proportioned output 261 and/or call for a desired ratio of the first fluid 211 to the second fluid 221 at the proportioned output 261. The processor 290 may then signal the speed control module 288 to adjust the speed of the first drive shaft 24 and/or the second drive shaft 34 accordingly, to attain the desired flow rate and/or fluid ratio at the proportioned output 261. In some embodiments, the pressure transducer 284 and/or the flow transducer 286 may provide feedback to the processor 290 for evaluation.

Additionally and/or alternatively, in embodiments in which the pressure transducer 284 and/or the flow transducer 286 is located in the proportioned output 261, the control system 205 may be able to maintain a constant pressure and/or flow rate at the proportioned output 261 by providing feedback to the processor 290 in order to adjust the speed of the first drive shaft 24 and/or the second drive shaft 34 (e.g., adjust the speed of the motor 22) accordingly.

FIG. 19C schematically illustrates another exemplary configuration of the control system 205 used with the pumping system 200. The control box 280 may include an on/off switch 282 controlling power to the processor 290. A user interface 294 communicating with the processor 290 may allow a user to input information into the processor 290. For example, a user may be able to input or select a desired flow rate and/or a desired ratio of the first fluid 211 to the second fluid 221 for an application. The processor 290 may process the information to determine the necessary rotational speed of the first drive shaft 24 and/or the second drive shaft 34 to attain the desired flow rate and/or desired ratio of the first fluid 211 to the second fluid 221. The processor 290 may send a signal to the speed control module 288 to control the speed of the motor 22 and/or the speed ratio through the transmission 30 necessary to attain the desired flow rate and/or desired ratio of the first fluid 211 to the second fluid 221. In some embodiments, the processor 290 may include a digital-to-analog converter (D/A converter) to convert a digital signal from the processor 290 to an analog signal sent to the speed control module 288, or the speed control module 288 may convert the signal to an analog signal to send to the motor 22 and/or transmission 30.

In this configuration, signals from the speed/rate counter 292 are input into the processor 290. For example, in some embodiments an analog signal may be sent to the processor 290 from the speed/rate counter 292. The processor 290 may include an analog-to-digital converter (A/D converter) to convert the inputted signals. In other embodiments, a digital signal may be sent to the processor 290 from the speed/rate counter 292. The processor 290 may process the signals and send an output signal to the speed control module 288 to further control the speed of the first drive shaft 24 and/or the second drive shaft 34 of the motor assembly 20. In some embodiments, the speed control module 288 may adjust the motor speed and/or the ratio through the transmission 30 to attain the desired rotational rates of the first drive shaft 24 (powering the first pump 12) and the second drive shaft 34 (powering the second pump 14) to attain the desired flow rate of a desired ratio of the first fluid 211 to the second fluid 221.

Thus, in such embodiments, the user interface 294 may be used to indicate to the processor 290 a desired flow rate at the proportioned output 261 and/or a desired ratio of the first fluid 211 to the second fluid 221 at the proportioned output 261. The processor 290 may then signal the speed control module 288 to adjust the speed of the first drive shaft 24 and/or the second drive shaft 34 accordingly, to attain the desired flow rate and/or fluid ratio at the proportioned output 261. In some embodiments, the speed/rate counter 292 may provide feedback to the processor 290 for evaluation to determine if the desired speed and/or flow rate has been attained.

In other embodiments, the control system 205 may be used to adjust the flow rate of the fluid mixture at the proportioned output 261 relative to the ground speed of a vehicle using the pumping system 200 to apply a fluid mixture during an application process to ensure that a desired quantity of the fluid mixture is applied, regardless of the ground speed of the vehicle during application. In such an embodiment, the speed of the motor 22 may be varied according to the ground speed experienced in order to ensure a constant quantity of the mixture is applied per area covered. Thus, the proportion or ratio of the first fluid 211 and the second fluid 221 in the fluid mixture at the proportioned output 261 may remain constant while the flow rate of the fluid mixture may be adjusted according to the ground speed of the vehicle. In such an embodiment, a pressure transducer 284 may be utilized to ensure that the pressure at the proportional output 261 remains constant as well.

One of skill in the art, in view of the above discussion of various pumping systems utilizing a pump assembly as described, would appreciate that other pumping system configurations and arrangements may be possible. For example, various components of a pumping system utilizing a pump assembly as described may be fluidly coupled together using hoses, pipes and/or fluid conduits extending between a fluid outlet of a first component to a fluid inlet of a second component to achieve a desired pumping system.

Those skilled in the art will recognize that the present invention may be manifested in a variety of forms other than the specific embodiments described and contemplated herein. Accordingly, departure in form and detail may be made without departing from the scope and spirit of the present invention as described in the appended claims. 

1. A system for pumping a first fluid and a second fluid in a desired proportion, the system comprising: an electric motor assembly having a first drive shaft and a second drive shaft, wherein during operation, the electric motor assembly drives the first drive shaft at a first rotational rate and the second drive shaft at a second rotational rate; a first pump driven at a first rate by the first drive shaft; and a second pump driven at a second rate by the second drive shaft.
 2. The system of claim 1, wherein the electric motor assembly includes a gear reduction assembly that drives the second drive shaft.
 3. The system of claim 2, wherein the first drive shaft extends from a first end to a second opposite end of an electric motor of the electric motor assembly, and the gear reduction assembly is fixed relative to the second end of the electric motor and is driven by or relative to the first drive shaft.
 4. The system of claim 3, wherein the second drive shaft is driven by the gear reduction assembly.
 5. The system of claim 1, wherein the first pump is a positive displacement plunger pump that includes a plunger situated in a cylinder for pumping the first fluid, the plunger of the first pump having a diameter and a stroke length; wherein the second pump is a positive displacement plunger pump that includes a plunger situated in a cylinder for pumping the second fluid, the plunger of the second pump having a diameter and a stroke length.
 6. The system of claim 5, wherein the diameter and/or stroke length of the second pump is/are the same as the first pump.
 7. The system of claim 5, wherein the diameter and/or stroke length of the second pump is/are different from the first pump.
 8. The system of claim 1, wherein the first pump includes a double acting simplex positive displacement pump, and the second pump includes a double acting simplex positive displacement pump.
 9. The system of claim 1, wherein the first pump and the second pump are configured to have substantially the same pumping capacity if the first pump and the second pump were driven at a common rate.
 10. The system of claim 1, wherein the first pump and the second pump are configured to have substantially different pumping capacities if the first pump and the second pump were driven at a common rate.
 11. The system of claim 1, further comprising: a first container for containing a first liquid, the first container in fluid communication with an inlet of the first pump; a second container for containing a second liquid, the second container in fluid communication with an inlet of the second pump; and a proportioned output in fluid communication with an outlet of the first pump and an outlet of the second pump.
 12. The system of claim 11, further comprising a first recirculating valve assembly situated in line with the outlet of the first pump, the first recirculating valve assembly recirculating the first liquid from the outlet of the first pump and back into the first container when a pressure at the outlet of the first pump exceeds a threshold value, and allows the first liquid to pass to the proportioned output when the pressure at the outlet of the first pump is below the threshold value.
 13. The system of claim 12, further comprising a second recirculating valve assembly situated in line with the outlet of the second pump, the second recirculating valve assembly recirculating the second liquid from the outlet of the second pump and back into the second container when a pressure at the outlet of the second pump is above a threshold value, and allows the second liquid to pass to the proportioned output when the pressure at the outlet of the second pump is below the threshold value.
 14. A system for pumping a first fluid and a second fluid in a desired proportion, the system comprising: a first pump having an inlet in fluid communication with a first container for holding a quantity of the first fluid, and an outlet; a second pump having an inlet in fluid communication with a second container for holding a quantity of the second fluid, and an outlet; an electric motor assembly for driving the first pump at a first cycling rate and the second pump at a second cycling rate; and wherein the outlet of the first pump and the outlet of the second pump are in fluid communication with an outlet of the system through respective check valves to prevent backflow.
 15. The system of claim 14, wherein the first pump and the second pump have substantially the same pumping capacity if the first pump and the second pump were driven at a common cycling rate.
 16. The system of claim 14, wherein the first pump and the second pump are configured to have substantially different pumping capacities if the first pump and the second pump were driven at a common cycling rate.
 17. The system of claim 14, wherein the desired proportion of the first fluid and the second fluid is not adjustable except by removing and then replacing one or more components of the system.
 18. The system of claim 14, wherein the first pump is a positive displacement plunger pump that includes a plunger situated in a cylinder for pumping the first fluid, and the second pump is a positive displacement plunger pump that includes a plunger situated in a cylinder for pumping the second fluid.
 19. A system for pumping a first fluid and a second fluid in a desired proportion, the system comprising: a first pump having an inlet in fluid communication with a first container for holding a quantity of the first fluid, and an outlet; a second pump having an inlet in fluid communication with a second container for holding a quantity of the second fluid, and an outlet, wherein the outlet of the first pump and the outlet of the second pump are in fluid communication with a first stage outlet; an electric motor assembly for driving the first pump at a first cycling rate and the second pump at a second cycling rate; a third pump having an inlet in fluid communication with the second container, and an outlet; and a fourth pump having an inlet in fluid communication with the first stage outlet, and an outlet, wherein the outlet of the third pump and the outlet of the fourth pump are in fluid communication with a second stage outlet, wherein the third pump is driven at a third cycling rate and the fourth pump is driven at a fourth cycling rate.
 20. The system of claim 19, wherein the third pump and the fourth pump are driven by the electric motor assembly.
 21. The system of claim 19, wherein the third pump and the fourth pump are driven by a different electric motor assembly.
 22. A method of combining a first fluid with a second fluid into a mixture of accurate predetermined proportions of the first fluid and the second fluid, the method comprising: pumping the first fluid through a first fixed displacement pump at a first flow rate, the first fixed displacement pump having a first displacement; pumping the second fluid through a second fixed displacement pump at a second flow rate different from the first flow rate, the second fixed displacement pump having a second displacement; and mixing the first fluid with the second fluid in a proportioned output downstream of the first fixed displacement pump and downstream of the second fixed displacement pump;
 23. The method of claim 22, wherein the first fixed displacement pump is powered by a first drive shaft of a motor assembly, and the second fixed displacement pump is powered by a second drive shaft of a motor assembly; wherein the motor assembly includes a motor powering both the first drive shaft and the second drive shaft.
 24. The method of claim 23, wherein the motor assembly includes a transmission, wherein the motor powers the first drive shaft at a first rotational speed, and wherein the transmission allows the motor to power the second drive shaft at a second rotational rate different from the first rotational rate.
 25. A method of providing an accurately proportioned liquid mixture of a first liquid and a second liquid to an applicator, the method comprising: providing a first pump having a first displacement; providing a second pump having a second displacement; actuating the first pump at a first cyclic rate by a motor, the first pump pumping the first liquid at a first fluid flow rate; actuating the second pump at a second cyclic rate by the motor, the second pump pumping the second liquid at a second fluid flow rate; the first pump pumping the first liquid to a first fluid output line when the pressure of the first liquid being pumped from the first pump is less than a first threshold pressure, and the first pump pumping the first liquid to a first fluid bypass line when the pressure of the first liquid being pumped from the first pump is more than the first threshold pressure; the second pump pumping the second liquid to a first fluid output line when the pressure of the second liquid being pumped from the second pump is less than a second threshold pressure, and the second pump pumping the second liquid to a second fluid bypass line when the pressure of the second liquid being pumped from the second pump is more than the second threshold pressure; and mixing the first liquid pumped from the first pump through the first fluid output line with the second liquid pumped from the second pump through the second output line in a proportioned output, the proportioned output having a desired ratio of the first liquid to the second liquid, wherein the proportioned output is in fluid communication with the applicator. 